There are many criticisms I could make of Christianity, but to me the biggest problem is also the central, most fundamental doctrine of Christianity, namely, Christ's supposed substitutionary atonement for the sins of mankind. The idea is that since humankind sinned by rebelling against God, that God must punish humanity for their sins, however, instead of punishing mankind, the story goes that God literally tortures and kills his own innocent son in man's place. This is the probably the most profoundly stupid and immoral doctrine anyone could come up with. Why would God torture and kill an entirely innocent person for the sins of others? Why could he not just forgive the sins of humankind without having to torture and kill his own son (who, paradoxically, also happens to be himself, but that's another issue for another post). I can anticipate that the response is that justice has to be delivered, and someone must receive a punishment, and Jesus willingly chose to take the punishment for mankind. But there is obviously a problem with this, since Jesus receiving man's punishment is not justice at all, in fact, it is simply indiscriminate vengeance on God's part. Basically, Christians are saying that God is so angry that he has to violently punish someone. It doesn't matter who he punishes, as long as someone gets punished. He can't just forgive humankind, he has to vicariously sacrifice himself to himself and punish himself to save humankind from his own indiscriminate anger. How can anyone think this doctrine makes the least bit of sense, from a moral or rational perspective? Do y'all actually think the guy who created the whole universe is this twisted and convoluted?