Christians believe that in order to be a Christian (follower of Jesus) you must repent of your sins and invite Jesus into your heart and make Him your Savior and Lord. That makes Him the leader of Christianity.
As for human leaders, there are many branches of protestant Christianity, so there is not one leader. Catholics believe the leader is the Pope.
Here are more answers:
- Jesus Christ is the leader, founder, and savior of Christianity, and the world.
- Jesus Christ did not practice Christianity. He practiced Judaism, preached Judaism, and even celebrated Passover. He is the reason for Christianity, but he is not the person who made or established it.