If premarital sex is so bad, why does it feel so good?

We cannot determine the morality of an action based upon how good it feels. Rapists and child molesters feel pleasure, but no one would doubt that their actions are immoral. Likewise, things that cause tremendous pain can be acts of great love, as when one person gives his life for someone else. If we measured the goodness of an act by the pleasure received, then adulterers would be virtuous and war heroes would be scoundrels.

If you want to know the morality of an act, ‘‘Do not conform yourself to this age, but be transformed by the renewal of your mind, that you may discern what is the will of God, what is good and pleasing and perfect’’ (Rom. 12:2, NAB).