Sin is an offense against God as well as a fault against reason,
truth, and right conscience. Sin is a deliberate thought, word,
or deed, or omission contrary to the Eternal Law of God. It is customary to distinguish between mortal and venial sins.

Copyrighted material from Saint Mary's Press,
Singer-Towns, Brian , , , Christian Morality, 9781599824468

Three elements determine the morality of any human
act is the object, that is, the specific thing the person is choosing to do, the intention of the person doing the action, and the circumstances surrounding the act. Both the object and the person’s intention must be good so it can be morally good

Copyrighted material from Saint Mary's Press,
Singer-Towns, Brian , , , Christian Morality, 9781599824468

Definition of Sin in the Catechism of the Catholic

Three Elements