God has no beginning and no end, so nobody created him - he has always been and his existence has no end. The main point of such fact is our beliefe in his existence. God created us and he doesn't want to show us his existence to make us believe in him. That is the main point in our religion - not to know but to believe in him by all our hearts!
We are all the children of God. The communication between the person and the God is called the pray. Its wery necessary for each of us to show the God our love and gratefulness and to show him that we really need him in our lifes.