... breaks rules on social responsibility, decency, matters of opinion and truthfulness.
I think all advertising should be banned unless they can prove what they say is true. This of course means religious advertising too. If they mention salvation, everlasting life, happiness etc. then plainly it would be against normal advertising standards.
This particular ad that fell foul of the ASA is purely propaganda aimed against a minority. How Christian is that?
My only reassurance is that many Christians would not agree with these tactics either (I hope) but as the comments in a previous post shows, some have little sympathy when minority groups are discriminated against if those groups do not share their views.