CCC 1854
Life in Christ›SECTION ONE MAN'S VOCATION LIFE IN THE SPIRIT›CHAPTER ONE THE DIGNITY OF THE HUMAN PERSON›IV. The Gravity of Sin: Mortal and Venial Sin
Sins are rightly evaluated according to their gravity. the distinction between mortal and venial sin, already evident in Scripture, became part of the tradition of the Church. It is corroborated by human experience.