[stripes1776]

St. Peter went to a synagogue. So did the other 1st century Popes...

But what about the 2nd and 3rd and 4th and 5th and 6th and 7th and 8th and 9th and 10th and 11th and 12th and 13th and 14th and 15th and 16th and 17th and 18th and 19th centuries?

[Cronos]

your question was “Since when do Popes go to mosques and synagogues?” — I pointed out that the 1st century Popes DID go to synagogues. Your question was answered.