That depends on what you mean by believe in God. Because you can intellectually believe in God without trusting in him, without loving him or knowing him. For example, Satan and his demons believe that God exists, but they also hate God. So just believing in God doesnt really mean anything.
Many times people will say, I believe in God, but it has absolutely no bearing on their lives. If they really knew who God was, they would live differently, they would put their lives in his hands. So mere intellectual belief that God exists isnt much of a big deal.