ahh, seems ya’ll need some backstory on this one. The "Groucho glasses" are from Groucho Marx, a famous American comedian from the 20th century. Known for one-liners such as, “That’s the silliest thing I’ve ever heard – and you’re the silliest thing I’ve ever seen!”. Jesus Christ is a biblical character from the first century AD, famous for forgiving sins. So for him to wear Groucho glasses and say "that"s the silliest sin I've ever forgiven" (and he would have forgiven a lot of them by now, right?) would probably strike most people who are familiar with Groucho, as funny. It’s tough to explain humor, but I hope this helps.