In Life of Pi why does Jesus make Pi become a Christian?
In the end, Pi joins three different religions, because all of them have something that appeals to him. As far as Christianity goes, the first thing that attracts Pi to is is the wonderful and psychologically interesting story that is attached to it. He is blown away by the fact that Jesus, the son of God, would pay for all of the sins of humanity. This is a confusing thing to Pi; as he ponders it, he thinks that it is so very sad that God would have to suffer for the evils of mankind. He thinks to himself that "divinity should not be blighted by death." Father Martin explains to Pi that the reason that Jesus did that was "Love." Pi, at first, is very bothered by Jesus, and his humanity, and the fact that he wasn't shining and all-glorious here on earth.
However, Pi thinks about Jesus and Christianity "for three days," and the more he thinks about it, the more he is compelled by it. He confesses of Christ, "the more I learned about Him the less I wanted to leave Him."
He is amazed that He would suffer so much for mankind, he is amazed at the humanity of the story, and, at the love that Jesus must have held for people in order to suffer so much for them. And, that is what compels him to join the Christian faith.
I hope that those thoughts helped a bit; good luck!