Why do people believe?
They believe because they have seen what belief in God does to a person.
Anyone can be loyal, truthful, sincere, respectful and caring without believing in God; there is one thing that a believer can do what no one can: to love unconditionally and to forgive, these is the essence of God which a believer has (Because He loved us first)
To love is to live like God first saw it when He brought this world into existence; He brought us into to existence to love us, to care for us and to have us all to Himself. To love is to forgive and forget, it means to move on without remorse and regret.
Let us not be a stumbling block to others, we need to live in love so that God shine through us, so that unbelievers see it as a relationship and not a religion.
Sometimes seeing is believing.