What Best Debunks Christianity and Religion?

I have been arguing that Christianity is basically bunk for seven years of daily Blogging now. I've learned a great deal in doing so from both sides of this debate and all others in between. Since I know Christianity is a delusion what greatly interests me are the reasons why Christians eventually leave the fold. After all, my single-minded goal is to convince them of this. My claim is that Christians leave the fold for so many different reasons because there are so many different reasons to do so. In fact, I've gone so far as to argue there isn't even a bad personal reason to reject the Christian faith in four parts (seen in reverse chronological order). I've also asked former Christians to share what convinced them to leave the fold and received over 200 comments of reasons which can be seen right here. But there are two reasons former Christians hardly ever mention so I don't focus on them at all, even though I think they are both serious ones worth considering. I find them to be basically wasted effort on my part if I were to focus on them, given that they don't work that well. Here they are, correct me if you think I'm wrong:

Th first one is to argue that Jesus never existed, that it's all a mythic story. On this issue just follow this link, and on that I rest my case. It might be that Jesus never existed and that it's all a mythic story. But I don't find many Christians at all leaving the fold until after they come to the conclusion the Bible is unreliable and the theology based on it is false, which is basically my focus.

The second one is to argue that human beings do not have free will, that our brains determine everything we think and do, that we are totally influenced by our DNA and environment. Don't get me wrong, this is probably the case, but believers have a much deeper psychological need to believe they have free will than they do about their religious faith. They will only come to think they don't have free will until after they reject their religious faith. When it comes to free will I think it's much better to argue that if we have it we don't have as much of it as we think, and that should be good enough.

I have a good friend who sings a one note song on the issue of free will, saying:
The entire Christian edifice stands on the need of salvation through faith that Jesus died to atone for our sins. There can be no sin without responsibility; and no responsibility if sins were caused by conditions beyond control.
Well, I could say this equally about a number of things having to do with Christianity. The entire Christian edifice stands on the evidence for the resurrection and that evidence is quite clearly insufficient to accept it. The entire Christian edifice stands on the credibility of Christians down through the centuries and it has no credibility to it. The entire Christian edifice stands on explaining how there could be a person who is 100% God and 100% man with nothing left out and everything included. The entire Christian edifice stands on whether evolution is true since the implications are enormous for the Adam and Eve myth and the need to atone for their sin by this God/Man. The entire Christian edifice stands on accepting 3rd 4th 5th hand testimony of ancient pre-scientific superstitious people. The entire Christian edifice stands on why a good all powerful and all knowing God allows so much massive intense and ubiquitous suffering in the world. The entire Christian edifice stands on whether Jesus was a false prophet because he predicted the coming of the "son of man" in his generation.

I just want my efforts to focus on that which actually does the best job in changing the religious landscape.

So I put it to my readers, what do you think? And are there other ineffective arguments we shouldn't focus on when debunking Christianity? Now I understand all too well there are many Christians who are impervious to reason so nothing will ever convince them otherwise. We're only talking about reasons that might best be able to convince a few of them otherwise.