As you know, former U.S. President Ronald Reagan passed away last week. On Friday, a state funeral service was held in the Washington National Cathedral, a Protestant Episcopalian institution here in DC. There were, to my knowledge, at least three Jews in attendance, including Natan Sharansky, Henry Kissinger and Rabbi Harold Kushner (a Conservative rabbi, who actually participated in the service, reading a few verses from Yishaayahu). What distinction is made between Catholic and non-Catholic places of worship, in terms of the permissibility of entering the place? Also, what disctinction is made between entering for religious purposes and for secular purposes (i.e., in order to participate in a lecture or view artwork)?
The prohibition to enter a church is because it is considered a place of idol worship, and although there are different kinds of Christians the custom is to regard all these places as places of idol worship. Hence, we do not enter them at all, not even for secular purposes such as you've mentioned. Rabbi Ro'i Margalit