The state of Original Sin is not the result of our personal deliberate sin, rather it’s the state of separation from God that occurred when our common forebearer effectively rejected God, as his God, with his personal sin of disobedience. From then on man would experience life at a fallen, lower level, a completely natural one in the sense that man’s will would now reign in his brave new world, for better or worse, without the direct controlling influence of union with God and His love and without the elevated status (immortality, justice, holiness, etc) which is part and parcel of that union as God’s gift.
God deemed it worthwhile that man should spend time in this exile, in this darkness, a lost condition relative to the light that man was made for, a light which results from immediate union with Him. Here we may come to experience and know our poverty, even amongst the various goods of creation, those things that we love here, and come to hunger and thirst for more than this world offers, to hunger and thirst for the righteousness and justice that only God can ensure, to hunger and thirst for Him as we also experience the evils that come from not knowing and walking directly with Him as Adam originally was privileged to do. “Apart from Me you can do nothing”, John 15:5. We’re here to learn the truth of that statement. Otherwise, from a position of privilege we might take our relationship with God for granted as Adam apparently did; we might not value God as we should, we won’t yet truly know and appreciate and love Him with our whole heart, soul, mind, and strength. We might not even want to know Him, preferring ourselves instead as the catechism teaches that Adam did. We might still keep looking over the fence, as we already continue to do now, carrying on the family tradition, thinking there might be something better “out there”, apart from God, in those lesser things that are merely His creation in the end.
God wants man to make a choice, the right choice, the choice that Adam failed to make in the beginning. It’s all about the human will, aligning itself with God’s will. Here, on this earth, we’re given the time and opportunity, with the help of revelation/knowledge and grace to work this out, to learn what we need to learn.
From the catechism:
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.