If god is omniscient,why does he have to get involved,he already know how it ends anyway?

Life never ends, it just changes form. I do not think that God is omniscient, who said that, and on what authority, God knows, what we will probably do, based on what we have done in the past, but does not interfere in our free will. That's just an excuse not to take responsibility for what we are doing, God is creator, just that, we are creation, co-creators and responsible for what we do with the opportunities of creation. Let's all have hope, that we won't let ourselves down!