This obligation flows from the virtue of faith, since belief in Christ is also belief in the Church and Christ’s promises to the Church. This teaching can be found in Sacred Scripture and Sacred Tradition, which includes the formal teaching of Popes and Councils regarding what has been revealed. It also includes what has been taught always and everywhere by the Church, as the entire Church cannot error in such matters. This common theology can also be found in accounts of the moral tradition by authors of noted orthodoxy and acceptance by the Magisterium (e.g. in English, Davis, Jone, Prümmer et alii.). It is NOT found in individual authors whose theological innovations are outside of that common tradition (e.g. contemporary consequentialists and proportionalists who deny that any act can be intrinsically evil, or who say that circumstances can sometimes justify an evil act).
