The Question and Answer section for Life of Pi is a great resource to ask questions, find answers, and discuss the novel.
Pi was a spiritual adventurer. He was not content with conformity. He thought these religions all had something to share: they were not mutually exclusive when it came to teaching.
The climax is tough to nail down. Within the context of your question, I would say that Pi is forced to grow up as soon as the ship sinks and Pi finds himself alone on the raft with the animals.
Pi's faith is three tiered; his faith is broad..... it is a house with many rooms. For many, this isn't the case. Each one of us has our own form of faith, and unlike Pi, we may not be able to see it from varied angles.