Our society lives and breathes this contradiction. We believe in determinism and demands justice. We believe in an omnipotent God and is sinful. On a personal level, there is quite literally nothing "you" can do to change yourself; to change oneself, one has to change to one that changes oneself. This is recursive. Looking at it this way, the important thing is to create an environment, situation, society that makes it easier to change oneself for the better. "Show me the incentives, and I will tell you what happens" as someone might say.