But to answer your question: "how"?
I don't go to church, I refuse to go to church, and I refuse to defend the church of man. They're a buncha fucking pharisees, anyway. So you won't see me defend or support or even try to justify the church.
That leaves the root of (in this case) christianity. How can I believe?
First, the entire foundation of the religion is Jesus, despite what some idiot with blow-dried hair might tell you. Tacitus, the heathen historian, Herodotus and other non-christian historians of the time refer to Jesus.
The fact that he existed is not in question. There is more historical record of Jesus than Alexander the Great.
Second, the basis of christianity is the resurrection, no matter what bullshit you hear in the church.
It's the second part that requires faith, although logic dictates that he came out of the tomb.
There is plenty of room in real believers for logic, faith, intelligence, and wisdom.