Do You Believe in God?

First of all I would ask, "whether we believe God exists?" Because until now many of us who do not believe in God, even those who 'religion', sometimes do not believe God can do everything!
From the first even now many people who believe that 'science' is not in line with 'religion. "
Right! If we based the conviction of man himself, it is not relevant or not in line. But if we believe all things came from God, then science is also from God, because we too from God.
These are basic questions that can sometimes make us often argued with friends, neighbors, coworkers, or with our spouse.

People often fear the changes, rejected, not accepted, have a lot of problems, pressures, difficulties, afraid to fail, humiliated, ostracized or dissociated and humiliated. But when we see and ask successful people, they are usually stories about him about his life journey full of challenges and obstacles, first of all not about success. Although in the end they told about his success. Where they talked about how they go through all obstacles, problems, pressures, difficulties, afraid to fail, humiliated, ostracized or dissociated and humiliated. That all is what makes them become successful; mature, not afraid to fail, people accepted, praised, even many people who want to be his friend.

So many religions, beliefs, different beliefs, and traditions, from first to this day many people who live to follow the life of his environment, his friends, his religion, usually follow from his parents, for Asian nations, especially Indonesia.
When someone starts to mature some people can have different beliefs. Why?
And there are also some do not want to move their belief, for various reasons, although there is no confidence in it. Why?  
Is this called maturity? or The belief that deep?