Originally Posted by Timelord Victorious.
Because he gave us minds, to be independent. He wanted to see if we would vary what he already saw might happen.
Think of it this way: you have a coin on which both sides are a head, there are no tails. You know when you flip it you'll get a head. Why would you flip it to test whether the outcome will be heads or tails? It's pointless and an utter waste of time.
Thing is, God doesn't 'forsee' the future, he is in the future, the present and the past at the same time. To say he is restricted by the forces of time would mean that he isn't omnipotent.
And so, he already knows how humans will die out. He knows what every single one of us will do in the next minute, because to him the minute is already happening.
He doesn't need to test theories, because he knows the outcome before the experiment even starts.
Edit: It also means that God created the unfaithful. You have no say in whether you're on the 'right path' or not.