From a very random dialogue on the web.
Poster 1: Catholicism is true christianity. The only true family of God. All other religion is man-made.
Poster 2: Actually, all religions are man made.If you can prove otherwise be my guest 🙂
Poster 3 (moi): Ah, but why should such an a priori assumption be more credible than faith? Remember, faith is not blind – it resolves eventually to sight. What I mean is, if I told you that I had crumbed fish for dinner tonight, and you believe me, you now have a new piece of knowledge based on hearing (because I really did have crumbed fish last night). Whether or not it is true depends on the credibility of the witness. That aspect, for Christianity, can be historically examined and tested, since it is a religion of eye witnesses and public revelations (unlike, um… I can’t think of any other, actually!).
Since you ask for proof, I’ll give you a challenge. Why not examine the historical evidence for Christ’s resurrection, starting with the websites of Peter Kreeft (www.peterkreeft.com) and William Lane Craig (www.reasonablefaith.org)? This is a good, central topic, because one can say to all Christians with St. Paul, “…if Christ be not raised, your faith is vain; ye are yet in your sins.” (I Corinthians 15:17).
Go on, I dare you – take the challenge from this agnostic-turned-Catholic. 😉 Here’s the link to the first article: http://www.peterkreeft.com/topics-more/resurrection-evidence.htm
And God bless ye’ – all, who seek, shall find. 🙂