The will of man has been the "prize" since Eden. Sin/evil would not even be possible, at all, unless for the freedom of created beings to oppose the will of God, even as that opposition is, in itself, a great evil and an anomaly in creation. We were made for union with God and His will- and are lost, sick, dead to the extent that we're outside of that will, alienated from Him, not knowing Him.
So salvation is the process by which God turns us back to Him, without overriding the will but by informing, moving, coaxing, drawing, chastising, appealing to us. Our experience down here in a world where good and evil are literally known, are experienced and experimented or toyed with directly, viscerally, are ingredients in this process, of our ultimately turning fully to Him and away from evil, meaning coming to love Him with our whole heart, soul, mind, and strength whereupon our justice or righteousness would be complete, perfected as goodness over evil is fully embraced.
God has a purpose or telos for man which we are created to attain, with His help. It will not be fully completed or consummated until the next life where we meet God face to face and are fully known just as we fully know -1 Cor 13. Because as we turn from evil here, in this life, and look towards the true Object of all human desire, Goodness, Personified, we've embarked upon a journey which has its end in the full captivation of the will, whereupon we would no longer even wish to be distracted by anything else, by lesser, created things over this one most high and beautiful Being, now in our presence in the next life as we've demonstrated in this life, to the extent that we're able and that we've succeeded in doing so, that He's right, that love is the ultimate good- and that He is love.
So enthralling and completely satisfying is the reward, the "simple" presence of God, that man could never want for anything else again-the right choice has now been confirmed in no uncertain terms. Here's a teaching I'm familiar with that sheds light, IMO, on our side of the equation, while not intending to compromise the absolute necessity of grace in it all:
1730 God created man a rational being, conferring on him the dignity of a person who can initiate and control his own actions. "God willed that man should be 'left in the hand of his own counsel,' so that he might of his own accord seek his Creator and freely attain his full and blessed perfection by cleaving to him."26
Man is rational and therefore like God; he is created with free will and is master over his acts.27
I. FREEDOM AND RESPONSIBILITY
1731 Freedom is the power, rooted in reason and will, to act or not to act, to do this or that, and so to perform deliberate actions on one's own responsibility. By free will one shapes one's own life. Human freedom is a force for growth and maturity in truth and goodness; it attains its perfection when directed toward God, our beatitude.
1732 As long as freedom has not bound itself definitively to its ultimate good which is God, there is the possibility of choosing between good and evil, and thus of growing in perfection or of failing and sinning. This freedom characterizes properly human acts. It is the basis of praise or blame, merit or reproach.
1733 The more one does what is good, the freer one becomes. There is no true freedom except in the service of what is good and just. The choice to disobey and do evil is an abuse of freedom and leads to "the slavery of sin."28
