Is it permitted to buy a property owned by a church?

Rav Yosef Kushner

Question: A church in my area is selling a building they own. Am I allowed to buy it?

Answer: We previously said that it is forbidden to fund activities in a house of avodah zara. There is, however, a clear halacha that discusses a case where a church that uses candles in its services had some extra candles and decided to sell them, and it concludes that a Jew may buy them. This leads to the question of why it is permitted to purchase these candles and, thereby, provide revenue for a church? 

The Taz answers that a church is not in the business of selling candles. The halacha is talking about a fluke case where the church had extra candles and decided to do a one-time sale, but this is not their real source of revenue. Since this is not the church’s general source of funding, it is permitted to buy these candles. 

In the case in question, it would seem that the answer would depend on the specific circumstances. If the church is not in the business of selling buildings and just happens to have one that someone left them in a will or that they somehow ended up owning, it would seem that, at least according to the Taz, it would be permitted to buy it. If, however, the church regularly makes real estate deals as a source of revenue, it would be forbidden.