A full explanation of the commandments of the Decalogue became necessary in the state of sin because the light of reason was obscured and the will had gone astray. 32
Catechism number 2072
Since they express man's fundamental duties towards God and towards his neighbor, the Ten
Commandments reveal, in their primordial content, grave obligations. They are fundamentally immutable,
and they oblige always and everywhere. No one can dispense from them. the Ten Commandments are
engraved by God in the human heart.