"I Am Heretic" is a satirical comic, often accompanied with commentary in the form of an article. Download the comic strip from this issue (right click, save as...).
The thing I probably deem the stupidest when it comes to Christianity is the "original sin" crap. First of all, the original sin is barely a sin; basically, Adam and Eve stole an apple; well, okay, it was an apple God had told them not to take. But does that justify that God banished mankind to a harsh existence, made women feel excruciating pain during childbirth, and then also murdered nearly every creature that lived (except two of each)? No, it doesn't; God is a genocidal sociopath who must have a heart blacker than Hitler's. He is certainly a very nice guy to worship, as he toys with us for his own twisted amusement.
Second, even if we say that the sin is that bad, it can't be blamed on all of mankind, because each individual is... well, just that—an individual. We are responsible for our own actions, not the actions of others. If we were responsible for what others did, wouldn't God be responsible for all the bad mankind has done, since he started it by creating us? If so, shouldn't God be punished, too? If so, I say yes. But fortunately for that cold-hearted bastard, I don't believe we're responsible for what others do.
Then there's that big stupid thing that happened later, when Jesus died to forgive all our sins, most importantly the very bad sin of having ancestors that ate fruit. All of that is stupid, from the original sin to the fact that God can't forgive us individually, so he forgives us en masse, as long as we are devout Christians. "Believe in me, or go to hell, bitches!" If God is so powerful, why would he need to become his own son and then die? Why couldn't he just forgive the sins? It kinda makes me think it was actually God's boss who said mankind was evil, and then the not-so-powerful God tried to cheat the system to help us. But that is not what the Christian faith says, nor something that would make much sense anyway.
Even all that I've written is just scratching the surface of the ocean that is the stupidity of the Christian origin story. Not only do I think the basic meaning of the story is bullcrap (we are all evil, because we inherited the sin of our ancestors when they didn't blindly obey God and ate some fruit), but the Bible is riddled with so many plot holes, I cannot see how a human brain could be incapable of perceiving that big pile of dung. But still a large chunk of the western world walks around with soiled shoes.