Why, I do believe that this priest has gone medieval on us! From the Catechism of the Catholic Church:
1951 Law is a rule of conduct enacted by competent authority for the sake of the common good. The moral law presupposes the rational order, established among creatures for their good and to serve their final end, by the power, wisdom, and goodness of the Creator. All law finds its first and ultimate truth in the eternal law. Law is declared and established by reason as a participation in the providence of the living God, Creator and Redeemer of all. "Such an ordinance of reason is what one calls law."
Alone among all animate beings, man can boast of having been counted worthy to receive a law from God: as an animal endowed with reason, capable of understanding and discernment, he is to govern his conduct by using his freedom and reason, in obedience to the One who has entrusted everything to him.
1777 Moral conscience, present at the heart of the person, enjoins him at the appropriate moment to do good and to avoid evil. It also judges particular choices, approving those that are good and denouncing those that are evil. It bears witness to the authority of truth in reference to the supreme Good to which the human person is drawn, and it welcomes the commandments. When he listens to his conscience, the prudent man can hear God speaking.
2242 The citizen is obliged in conscience not to follow the directives of civil authorities when they are contrary to the demands of the moral order, to the fundamental rights of persons or the teachings of the Gospel. Refusing obedience to civil authorities, when their demands are contrary to those of an upright conscience, finds its justification in the distinction between serving God and serving the political community. "Render therefore to Caesar the things that are Caesar's, and to God the things that are God's." "We must obey God rather than men":
When citizens are under the oppression of a public authority which oversteps its competence, they should still not refuse to give or to do what is objectively demanded of them by the common good; but it is legitimate for them to defend their own rights and those of their fellow citizens against the abuse of this authority within the limits of the natural law and the Law of the Gospel.
1778 Conscience is a judgment of reason whereby the human person recognizes the moral quality of a concrete act that he is going to perform, is in the process of performing, or has already completed. In all he says and does, man is obliged to follow faithfully what he knows to be just and right. It is by the judgment of his conscience that man perceives and recognizes the prescriptions of the divine law:
Conscience is a law of the mind; yet [Christians] would not grant that it is nothing more; I mean that it was not a dictate, nor conveyed the notion of responsibility, of duty, of a threat and a promise. . . . [Conscience] is a messenger of him, who, both in nature and in grace, speaks to us behind a veil, and teaches and rules us by his representatives. Conscience is the aboriginal Vicar of Christ.
1781 Conscience enables one to assume responsibility for the acts performed. If man commits evil, the just judgment of conscience can remain within him as the witness to the universal truth of the good, at the same time as the evil of his particular choice. The verdict of the judgment of conscience remains a pledge of hope and mercy. In attesting to the fault committed, it calls to mind the forgiveness that must be asked, the good that must still be practiced, and the virtue that must be constantly cultivated with the grace of God:
We shall . . . reassure our hearts before him whenever our hearts condemn us; for God is greater than our hearts, and he knows everything.