Posit: God is omnipotent. All knowing, all seeing. God knows everything about everything, all that has been, all that is and all that will ever be. Christianity teaches this as the very basis of existence itself, and if you believe in God, you must accept this to be the absolute truth.
In the Christian tradition, we are also taught that God has given Mankind free will. The ability to make our own choices and to determine our own destiny. That there is no destiny, other than what we make for ourselves.
As Adam chose to bite the apple in the Garden of Eden, so are we all free to choose what we will do, and if that will be good or evil. But if God knows everything, then he must have known that Adam would bite the apple. Even before the apple that Adam would bite, or the teeth that Adam would bite with, were created.
If Johnnie Cochran were still alive, I’d say he could make a pretty good argument that the fall of Man was God’s fault. Because if God hadn’t created Eve then she couldn’t have tempted Adam and therefore the creation of Eve was contributory negligence.
But I digress. If God knows everything about everything and all that has been, is, and will ever be, then he must have known everything that would ever be even before he set about to create the Heavens and the Earth. Before anything even existed, God knew the outcome of the whole stinking morass.
So where’s free will in this? If God knew, before the dawn of time, exactly everything that would happen everywhere, including the choices I would make along the way, then how can we say there is no destiny?
It follows that anyone that believes they have no destiny – that they truly control their own life – must not believe in God, for only without a God in control of the Universe can there be anything happen that was not known in advance.
So, either the path that we (and everything else, alive or not) take through existence is completely known in advance and thus predetermined, or there is no God.