Much ink has been utilized in discussing this topic spanning over a millennium, from Rishonim to contemporary poskim. This essay will try and highlight the major points of discussion and perhaps add a few insights in line with our Sages dictum “ee efshar l’beit midrash b’lo chidush.” We will also bring some practical halachic ramifications and conclusions.
At the outset, the first point of discussion is to clarify the status of Christianity. Is it considered idolatry or not? Thereafter, we will discuss entering a house of idolatry, and whether there are certain times and extenuating circumstances that the Halacha takes into consideration.
The status of Christianity
There are varied opinions among the Rishonim whether Christianity is considered idolatry or not. The Rambam is famous for his categorical decision that all Christians are idolaters. He states unequivocally in his commentary to the Mishna: “You should know that this Christian nation who have messianic claims across all their sects, are all idolaters.” The Meiri held the exact opposite, giving them an elevated status of “Umot hagedurot bedarkei hadatot.” Rav Saadia Gaon held an intermediary position classifying four distinct sects of Christianity, of which only some were defined as idolaters.
Tosafot quote a novel approach of Rabbeinu Tam to the issue, and the Acharonim strongly debated what Rabbeinu Tam actually meant by his words, as we will clarify.
The Rema, Shach, and others understood Rabbeinu Tam to mean that there is no prohibition for non-Jews to believe in G-d and another deity b’shituf (as some form of duality or partnership). This would only be prohibited to Jews. The Noda Biyehuda vehemently argued that this was not the intention of Rabbeinu Tam. Rabbeinu Tam only stated that Jews are not obligated to concern themselves if a non-Jew would take an oath b’shituf, i.e., when swearing, he would mention the name of G-d together with the name of a deity. The Noda Biyehuda explains that for a non-Jew to take such an oath is not prohibited to non-Jews, but it is definitely forbidden for a non-Jew to believe in shituf. This is also the opinion of the Minchat Elazar, Shaar Efrayim, and other Acharonim. However it seems that the accepted opinion of modern day poskim is like the Rema.
How this relates to defining a church as a house of idolatry
The ramifications of Tosafot’s opinion, even according to the lenient interpretation of the Rema and Shach, have also been highly debated.
Some claimed that since according to Tosafot, Christianity is not considered idol worship for non-Jews and Christians are not considered idolaters, a church is therefore not considered a house of idol worship either (even though it is still prohibited to enter for other reasons as we will see).
Others claim that even according to Tosafot, although a non-Jew who follows Christianity doesn’t transgress idolatry as this type of worship is not forbidden to them; nevertheless since for a Jew it would be considered idol worship, hence we view a church as a house of idolatry.
The Rambam’s opinion revisited
As stated above the Rambam wrote in numerous places that Christians are considered idol worshippers. However some claim that the Rambam’s categorical claim is not relevant to many sects of Christianity in modern times. They argue that there have been many theological changes in Christianity and today many sects would not be considered idolaters according to the Rambam. In order to understand this claim we need to define the nature of idol worship.
From the language of the Rambam one can deduce that there are two aspects of idolatry.
The first component is “avodah” – service, and the second component is “zarah” – foreignness.
The Rambam describes the component of “foreignness” in his introduction to perek chelek in the fifth foundation of the principles of faith. He explains there that the prohibition of serving anything other than G-d, i.e., idolatry, includes any service of other powers.
The second component of “avoda” – service, refers to the action performed to that foreign object or power. Only once one performs the action is one punished with the death penalty. It is clear that someone who only looks at idols is not liable to the death penalty. The question is what is defined as an act of serving this idol? The Mishna in Sanhedrin (60b) states that only certain actions such as slaughtering a sacrifice, burning incense, pouring libations, bowing, or declaring “you are my god” are considered acts of serving idolatry liable to the death sentence.
The question is: What halachic status is given to one who only has thoughts of avoda zara without any actual actions?
Dror Fiksler and Gil Nadel claim that many sects of Christianity today do not have both elements of thought and service of idolatry, and would not be considered idolaters according to the Rambam.
Although Christianity in the times of the Rambam included both aspects of foreignness (asserting certain power to the Trinity) as well as many classical acts of service, today many have changed their way of service so that it no longer includes classic rituals of idolatry. In this case although they still believe in the trinity, they would be defined as non-believers or apostates.
Furthermore, many sects have renounced their faith in the trinity altogether, and quite possibly are not considered idolaters even in terms of thought alone. Nevertheless, if a Jew were to believe this, he would be considered a complete apostate, as he denies Torat Moshe.
Is there still reason to define all of Christianity as idolatry?
Rav Yaakov Ariel argues the above points. He holds that thought alone can define a person as an idolater, and brings proofs to this from the Talmud, as well as the words of the Rambam himself in the Sefer Hamitzvot. However in my humble opinion his arguments are not completely decisive for the term idolatry is never actually used in any of these places, only that there is a prohibition involved.
Nevertheless his second argument is very compelling even though it is based on pragmatic considerations. He argues that even if we assume that certain sects are not considered idolatry, it becomes extremely difficult to ascertain which sects fit into this category, due to the multitude of sects and the need to understand the deep theological underpinnings of each sect, something that may cause many to err.
Is it permitted to enter a Church?
All the poskim have stated categorically that it is prohibited to enter a church. However regarding the level of the prohibition, its source, and if there are times when one can be lenient, there are varied opinions.
The prohibition to enter a house of Idolatry
The source of the prohibition is found in a Mishna in Masechet Avoda Zara stating that it is prohibited to travel on a road leading to a house of idolatry. From here it seems clear that actually entering the edifice is prohibited. Two main reasons for the prohibition are suggested by the Rishonim.
Rashi explains that the prohibition is based on chashad, the suspicion that a person who goes there might be worshiping idolatry. This is also the understanding of the Rashba and Ritva. They explain that this is the reason the Mishna permits traveling on such a road if it leads to other places as well, for there won’t be any suspicion involved.
The Ritva though has a unique dimension to his opinion here not shared by the other commentaries. He writes that this chashad (which is a rabbinic gezeira) is considered avizrayu d’avoda zara (an accessory to Avoda Zarah) and one would have to give up one’s life before entering a house of idolatry. On the other hand, the Ritva writes that where there is no chashad it would be permitted to enter even for the sake of a financial loss (implying that where there is no reason, one should still desist).
2. Concern lest one’s heart is drawn after them
Tosafot suggest another reason: “Lest one’s heart is drawn after idolatry.” This can be deduced from their commentary to a sugya in Avoda Zarah. The Gemara relates that Rav Chanina and Rav Yonatan were travelling and came to a junction. One road passed a house of harlots, while the other road passed a house of idolatry. In the end they decided to travel the road that passed the house of idolatry. Tosafot there explain that they did not want to approach a house of idolatry based on the verse “do not come close to the house’s opening,” and their formulation intimates that the problem is that one’s heart might be led astray. This is also intimated in the words of the Rambam in the Guide for the Perplexed, although admittedly this is by no means explicit. The Rosh opines that it gives honor to idolatry, which might draw one’s heart away.
According to both reasons it seems that the prohibition is a rabbinical decree. According to Rashi and those that share his opinion, there is room to be lenient in certain cases if there is no chashad. Even according to Tosafot who hold that there is an independent prohibition (leading one’s heart astray), there still might be room to be lenient in extenuating circumstances, as it is a rabbinical prohibition based on a verse in Mishlei, or perhaps only a hanhaga tova, a proper way to act. Indeed, most poskim hold that the prohibition is rabbinic in nature. However, the poskim viewed it in the most stringent terms to the extent that it was unclear to some opinions if one could enter even in life threatening situations.
As mentioned above, the Ritva holds that it is prohibited to enter a house of idolatry even if one’s life is in danger. The Rashba is in doubt whether one can enter even for the sake of the community, and it is possible that even in times of danger he would hold it is prohibited. The Ran holds that it is certainly permitted if one is in danger and the opinion of the Rosh is debated whether it is permitted only when one is in danger or even for financial loss.
The Shulchan Aruch rules that it is permitted to enter a house of idolatry if one’s life is in danger. Implicit in the Shulchan Aruch’s words is that for the sake of work, etc. it would be prohibited.
Impurity of Idolatry
There may be a third reason for distancing oneself from a house of idolatry alluded to in the Rambam. The Rambam writes in Hilchot Avot Hatumah: “The impurity of idolatry is rabbinical and there is a hint to it in the Torah: “Remove the foreign gods among you and purify yourselves and change your clothing.” It seems from the Rambam as if the idea that idolatry causes ritual impurity is related to the notion of distancing oneself from idolatry. There thus seems to be a rabbinic prohibition here of coming too close to idolatry.
Even according to those opinions that Christianity today is not considered idolatry, the idea of distancing oneself from heresy based on “the rabbinic impurity” still remains. In this context, the poskim cite the words of Rav Chaim Pelagi who wrote explicitly that there is impurity in a church, and these impure forces cling to a person’s soul. This is another reason to distance oneself from entering a church, and this reason is also rooted in a rabbinic decree.
Receiving benefit from Avoda Zara
Up until this point we have discussed three separate reasons for why it would be prohibited to enter a house of idolatry. However according to all three, the prohibition is rooted in a rabbinic decree (even if one might have to endanger one’s life for this specific rabbinic prohibition).
Another reason discussed by some authorities (though many others seem to have ignored this point) is the possible prohibition of receiving benefit from avoda zara. Benefitting from avoda zara is clearly a Torah violation based on the pesukim in Devarim (7:6 and 13:18), and would change the nature of the prohibition from the lower severity discussed until now.
From the Mishna in Avoda Zara 47b it is clear that if avoda zara was placed in the house, the house itself becomes meshamshei avoda zara. The Rishonim on the sugya explain that if idol worshipers placed the avoda zara there in a permanent fashion, did not nullify it, and practiced rituals of avoda zara there, there would be a Torah violation of receiving benefit from this house.
If one accepts this approach, it needs to be clarified as to what constitutes benefit that would be prohibited. Would entering the building in order to look at the architecture or to hear a concert (for example if an external party hired out the venue and there is no connection to the church itself) be considered receiving benefit?
Defining receiving benefit from avodah zara
The Gemara relates that it is prohibited to sit under the shade of an ashera tree (a tree that was planted and served as idolatry) due to the prohibition of receiving benefit from avoda zara.
Tosafot ask how according to this Rabban Yochanan Ben Zakai could sit in the shade of the Beit Hamikdash and teach Torah. After all, just as (lehavdil) there is a prohibition to receive benefit from idolatry, there is also a prohibition to receive benefit from a consecrated item. Tosafot’s first answer is that regarding the Heichal (the edifice of the Beit Hamikdash), “Heichal letocho asui,” literally meaning that the Heichal was made for its inner usage. In other words, the shade created outside the building is not the main reason for the building, but merely an indirect result, as opposed to the shade of the tree, which is a major function of a tree. Tosafot’s second answer is that “the stringencies of idolatry are different.”
According to the first reason, it seems that shade outside a house of idolatry is permitted, as it’s not the main function of the building. But the shade inside the building should definitely be forbidden, similar to the shade under the ashera tree. Based on this answer, one could deduce that entering a house of idolatry would be a Torah violation, similar to sitting under an ashera tree.
However, according to the second answer of Tosafot, it stands to reason that shade of a tree or a building is in essence permitted, and is not considered benefit. The reason one is prohibited to sit under an ashera tree then is due to the stringency of avoda zara. This implies that it is not the regular definition of issur hanaa from the Torah, but rather a stringency of the Rabbis. Hence there still might be room to be lenient in extenuating circumstances such as eiva (causing enmity).
The parallel sugya in the Yerushalmi understands that there is no prohibition of issur hanaa violated by sitting under an ashera tree. Rather, the entire prohibition is due to the stringency of avodah zara. One could perhaps argue compellingly that the benefit from the shade is not a positive benefit, but rather eliminates a negative aspect (the sun’s rays) and this is considered benefit of no substance (hanaa shein bo mamash). Such a benefit could also be achieved in other ways such as when it is cloudy or at night. .
It is possible that many poskim did not discuss the possibility of isur hanaa for a number of other reasons as well. First, for many poskim, a church is not considered a house of idolatry. Second, even if one assumes that it is, one could argue that shade is not considered a benefit of substance included in the prohibition, based on the second answer of Tosafot and the simplest reading of the Yerushalmi. Perhaps even the first answer of Tosafot can be reconciled with this suggestion (albeit with difficulty). Therefore, based on all the above reasons, many poskim did not see fit to categorize entering a church as a Torah violation.
Are there extenuating circumstances when one might be able to be lenient?
The poskim have stated that it is clearly prohibited to enter a church. Nevertheless, some poskim are lenient in certain extenuating circumstances.
1. A concern for causing enmity
There are times when communal leaders are invited to important state ceremonies that take place in churches, and refusing to go could cause great resentment and enmity towards the Jewish community. Based on what we have seen above, if one holds that there is a Torah violation of receiving benefit, these circumstances would not permit entering a church as we are generally not lenient on a Torah obligation due to eiva. However, many poskim are lenient in these scenarios based on the assumption that it is a rabbinic prohibition. This leniency has two very important limitations. First, one needs to clarify that there is a real concern for eiva. Second, Rav Asher Weiss points out that even if a communal leader or Rabbi needs to enter, he is definitely prohibited to pray there or say Tehillim, as it is forbidden to pray in a house of idolatry. Moreover, it should be noted that Rav Ovadia Yosef ruled against this leniency outright, despite taking the position that the prohibition is only rabbinic in nature.
- Using the parking lot as a short cut
Rav Moshe Feinstein permitted using the parking lot of a church as a short cut as long as one does not enter the actual precinct itself. Yet he forbade children playing in a room adjacent to the main precinct and owned by the church even though there were no idols or artifacts of worship.
- Voting in a room connected to a church
Rav Moshe Shternbuch was lenient with regard to voting in a room connected to a church (a scenario that is very common in North America, where churches are often used as voting stations), where there was a separate entrance and the room was used for other purposes such as seminars. He points out that since one of the main reasons for the prohibition is marit ayin, since everyone knows that one is going there to vote, it would be permitted.
- A church that is no longer in use
Although most poskim hold that such a building still retains the halachic status of a church, there is a minority opinion of Rav Chaim David Halevi that a church which no longer functions as such is permitted to enter, even for tourism. This opinion is mentioned in Responsa B’mareh Habazak, which elaborates on the issue and also discusses other scenarios.
May Hashem enlighten our eyes with his Torah and save us from any sin and iniquity.
 Masechet Chagiga 3a
 Commentary to Mishna, Masechet Avoda Zara 1:3
 Beit Habchira, Bava Kamma 113b and Yoma 84a
 Emunot V’deot pp. 83-85 in the Rav Kapach edition. Today there are many more sects and we will deal with this issue later on in the essay.
 Tosafot, Masechet Sanhedrin 63b s.v. asur. See also the Rosh there and the Ran at the end of the first chapter of Avoda Zara.
 Rema, O.C. 156:1
 Shach, Y.D. 141:7
 See, for example, the Yaavetz (Mor Uketzia 242), Pitchei Teshuva Y.D. 147:2.
 Noda Biyehuda Tanyana, Y.D. 148
 Minchat Elazar 1:53-3
 Shaar Efrayim, siman 24
 Rav Chaim David Halevi, former Chief Rabbi of Tel Aviv, Techumin vol. 9 pp. 73-78; Rav Shlomo Aviner, Techumin vol. 8 pp. 368-370, among others.
 Responsa Melamed Leho’il 1:16; Yabia Omer 2:11; Darkei Teshuva Y.D. 150:2
 See, for example, Hilchot Avoda Zara 9:4.
 Alternatively, if there was a specific way of serving an idol, such as throwing stones at Markulis or defecating in front of Peor, one would also be liable.
 Techumin vol. 22, “Christianity in Contemporary Times (Heb.)”
 Rav Ariel wrote a rebuttal to Fiksler and Nadel’s article, printed as an appendix at the end.
 See Kidushin 39b and Rambam, Sefer Hamitzvot, Lo Taaseh 1 (avoda zara).
 In Responsa Mayim Chaim (vol. 2, Y.D. 108), Rav Shalom Mashash testifies about himself that he delved into the matter with a priest and came to the conclusion that they are not idolaters. Melech Shapira (Milin Chavivin p. 44) commented that if Rav Mashash understood the priest correctly, the priest himself made heretical statements against his own religion.
 Igrot Moshe, Y.D. 3:129:6; Tzitz Eliezer 14:91; Yabia Omer 2:Y.D 11; Yechaveh Daat 4:45; Minchat Asher, Parshat Vaeira, תשע”ב; Responsa Chaim B’yad of Rav Chaim Pelagi 26.
 Mishna, Masechet Avoda Zara 1:4
 Rashi, commenting on the Mishna, Masechet Avoda Zarah 11b
 Rashba ibid. (printed on 12b), s.v. bizman shehaderech
 Ritva ibid., s.v. ir sheyesh
 Tosafot, Masechet Avoda Zarah 17b s.v. neizil
 Masechet Avoda Zarah 17a
 Mishlei 5:8
 Guide for the perplexed 3:37
 The Tur understood the Rosh as being lenient only in life-threatening situations. Some Acharonim understood that he was lenient even for financial concerns.
 Hilchot Avot Hatuma 6:1
 Chaim B’yad 26
 See Masechet Avoda Zara 51b and Rambam, Hilchot Avoda Zarah 7:2.
 Ritva ibid. and Ran on the Rif
 Masechet Avoda Zarah 48b
 Ibid. s.v. lo yeshev
 Masechet Pesachim 26a
 This could answer a seeming contradiction in the words of the Ritva, who explained in his commentary on 11b that it is due to chashad, yet didn’t mention a problem of issur hanna; while he clearly holds that a house of idolatry is considered meshamshei avoda zara and there is a Torah violation of receiving benefit from it. Perhaps the Ritva understood like the second answer of Tosafot, that shade is not really considered benefit, and we are only stringent for the actual avoda zara and not for meshamsheha.
 Yerushalmi, Avoda Zara 3:11
 From the Responsa Igrot Moshe, Y.D. 3:129:6, it seems that Rav Feinstein felt there was a Torah violation of benefiting from noyei avoda zarah, items made to beautify the idol, in this case due to the artwork. This also seems to be the opinion of Rav Moshe Shternbuch.
 See, for example, Yabia Omer 2:11 who clearly defines it as such, yet does not raise the issue of a Torah violation of issur hanaa of meshamshei avoda zara.
 According to Tosafot’s first answer that shade is included in the prohibition of receiving benefit, one could explain the phrase “heichal letocho asui” in a different manner. A building’s main function is not for shade. Therefore, the benefit of shade that one receives from a building is not a Torah violation, only a stringency of avoda zara. But in the case of a tree, whose main function is for shade, when one stands underneath it one clearly is receiving benefit, for why else does one stand under the tree? This, in turn, defines the shade as a benefit of substance. A building, on the other hand, has many functions and if one enters a building, it is not clear that one is doing so for shade. Therefore, even if one did enter for shade, it could be argued that it is not considered a benefit of substance.
 Shach, Yoreh Deah 149:1; Responsa Pri Hasadeh 2:4; Tzitz Eliezer 14:91 and others.
 Cf. Magen Avraham and Kovetz shiurim, Bava Batra 56
 This has been the psak of the London Beit Din for over a century.
 See Shemot 9:29 and Rashi and Ramban there in the name of the Mechilta. See further elaboration in the Minchat Asher ibid.
 Igrot Moshe Y.D 3:129:6
 Igrot Moshe O.C 4:40:26
 Teshuvot Vehanhagot 2:410
 Responsa B’mareh Habazak 8:35