So even if you were born this way...

Clearly, (an) understanding of original sin is essential when we are speaking of the moral quality of human inclinations. Because of original sin, a certain disorder resides in the human heart such that one often desires that which is contrary to the moral law. Therefore, even if homosexual inclinations are entirely inherited, this does not mean that they necessarily correspond with human nature in the original sense, as God intended it. Moreover, as Christ made clear in his preaching, it is the original, created order that has normative weight to it, not this transitory fallen state:

Some Pharisees approached him, and tested him, saying, “Is it lawful for a man to divorce his wife for any cause whatever?” He said in reply, “Have you not read that from the beginning the Creator ‘made them male and female’ and said, ‘For this reason a man shall leave his father and mother and be joined to his wife, and the two shall become one flesh’? So they are no longer two, but one flesh. Therefore, what God has joined together, no human being must separate” (Mt 19.3-6).

Thus, the inclinations that arise in the human heart must be tested according to objective moral norms because the human nature we encounter in this age of history, though wounded by sin, is still called to the same norms of behavior intended by God “from the beginning.” Why? Because God created us “out of love for love” (John Paul II, 1981, no. 11); His wise, loving plan permeates all of created reality. Therefore, to follow the norms given to us by our Creator and Redeemer is in no way an imposition or alienation but a call to happiness. The moral law given to us by God is a blueprint by which human beings can achieve their fulfillment. This implies another fundamental truth of Christian anthropology: human nature is wounded, but it is not totally corrupted. Man still has freedom. Though weakened by sin and prone to misuse, the human person still possesses the ability to make free moral choices and, by cooperating with God’s grace, grow in holiness and maturity.

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 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 direct toward God, our beatitude (CCC, no. 1731).

The proper, beatifying use of freedom requires God’s grace. Only with His help can we properly see the truth and act in accord with it. Thankfully, God desires all men to be saved and abundantly supplies the means for it to happen. - Andrew J. Sodergren, M.S. John Paul II Institute for Studies on Marriage and Family