A true humanism must recognize that sin is “an integral part of the truth about man” because human beings are moral actors.  Men and women can, and do, commit evil acts, and those acts open up a double wound in the sinner, and in the sinner’s relationships with family, friends, neighbors, colleagues, even strangers. (13.1., 13.2, 15.4)

To take sin seriously is to take human freedom seriously, John Paul suggests, and that is why the personal character of sin can never be diminished.  Psychological, cultural, and social factors condition the way people make their moral choices.  those factors, if strong enough , can constrain freedom and limit moral responsibility.  But these facts of life could not be understood in ways that erode a deeper truth – that sin is a result of an act of personal freedom, which is a crucial dimension of human dignity.  (16.1)

John Paul II : “Reconciliatio et Paenitentia” signed on December 12, 1984 as a  Post-Synod inspired document.

Cited in Weigel, George WITNESS TO TRUTH (biography of Pope John Paul II)