Just to support Mod 80’s point about Christianity, here is an incredible letter from R’ Yaakov Emden, if you have the patience to read through the old print (I think it’s out of print since then):
http://hebrewbooks.org/pdfpager.aspx?req=20383&st=&pgnum=66&hilite=
Start from about halfway down. You can find a English translation floating around on the internet.