One Should Speak Freely Against Heretics and Schismatics
False ecumenism, so widespread and common in our days and coming from high ecclesiastical authorities, affirms that is not charitable to condemn heretics, schismatics, and other enemies of the Catholic Church.
To stop attacking these people is falsely presented as an act of love, and a obligation of Catholics. The truth, however, is the opposite as one can read
in the Saints and Doctors of the Church.
We transcribe below a text of St. Francis of Sales, Doctor of the Church, universally known for his goodness and charity. He strongly advises us to condemn the enemies of the Church.
The declared enemies of God and His Church, heretics and schismatics, must be criticized as much as possible, as long as truth is not denied.
It is a work of charity to shout: "Here is the wolf!" when it enters the flock or anywhere else.
(Introduction to the Devout Life, part III, chap. 29)
"So let us be confident, let us not be unprepared, let us not be outflanked, let us be wise, vigilant, fighting against those who are trying to tear the faith out of our souls and morality out of our hearts, so that we may remain Catholics, remain united to the Blessed Virgin Mary, remain united to the Roman Catholic Church, remain faithful children of the Church."- Archbp. Lefebvre 1980