In 1989, Edouard Cardinal Gagnon, who served as President of the Pontifical Council for the Family, described a conversation he had with [now-Blessed] Pope John Paul II:
“The Pope told me, ‘Error makes its way because truth is not taught. We must teach the truth, repeat it, not attacking the ones who teach errors because that would never end—they are so numerous. We have to teach the truth.’ He told me that truth has a grace attached to it. Anytime we speak the truth, we conform to what Christ teaches and what is being taught by the Church. Every time we stand up for the truth there is an internal grace from God that accompanies that truth. The truth may not immediately enter into the mind and heart of those to whom we talk, but the grace of God is there and at the time they need it, God will open their heart and they will accept it. He said that error does not have grace accompanying it. It might have all the external means, but it does not have the grace of God accompanying it. This encouraged me very much.”
Quoted by Thomas Langan, The Catholic Tradition, page 371