3987. So in order that there may be true faith, the higher knowledge of a faith founded in love must take root, so that if one does anything other than what is good and what is in accord with higher knowledge of faith, it goes against one's conscience. Therefore one who has true faith does the works of charity, nor can such a person do otherwise, being led by the Lord.
3987. Wherefore in order that there may be a true faith, the knowledges of faith which are founded in love are to be so irradicated, that if one does anything but good, or anything that is not in accordance with the knowledges of faith, a violence shall be done to conscience; wherefore whoever is in true faith he is in the works of charity, nor can he be otherwise. Thus he is led by the Lord.
3987. Quare ut vera fides sit, cognitiones fidei, quae fundatur in amore, ita erunt irradicatae, ut si aliter faciat quam bonum, et quam secundum cognitiones fidei, quod conscientiae contrarium sit, quare qui in vera fide, is in operibus charitatis est, nec aliter potest facere, ita ducitur a Domino.