Ephesians 5:6

These people he calls "children of disobedience"; for there are many who make light of the promise of a heavenly kingdom.… They disbelieve; they have no faith. The wrath of God comes upon the children of disobedience. Disobedience is epitomized by the devil they serve. Therefore they are said to be his children.

And just as then, those who led vicious lives, and put other people astray, were condemned and cast out, so also even now the offending eye is plucked out, and the foot and the hand, lest the rest of the body perish in like manner. And we have the precept: "If any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner, with such an one no not to eat." And again does the apostle say, "Let no man deceive you with vain words; for because of these things cometh the wrath of God upon the sons of mistrust. Be not ye therefore partakers with them." And as then the condemnation of sinners extended to others who approved of them, and joined in their society; so also is it the case at present, that "a little leaven leaveneth the whole lump."

Let the lapsed, however, who acknowledge the greatness of their sin, not depart from entreating the Lord, nor forsake the Catholic Church, which has been appointed one and alone by the Lord; but, continuing in their atonements and entreating the Lord's mercy, let them knock at the door of the Church, that they may be received there where once they were, and may return to Christ from whom they have departed, and not listen to those who deceive them with a fallacious and deadly seduction; since it is written, "Let no man deceive you with vain words, for because of these things cometh the wrath of God upon the children of disobedience; be not ye therefore partakers with them." Therefore let no one associate himself with the contumacious, and those who do not fear God, and those who entirely with draw from the Church. But if any one should be impatient of entreating the Lord who is offended, and should be unwilling to obey us, but should follow desperate and abandoned men, he must take the blame to himself when the day of judgment shall come. For how shall he be able in that day to entreat the Lord, who has both before this denied Christ, and now also the Church of Christ, and not obeying bishops sound and wholesome and living, has made himself an associate and a partaker with the dying? I bid you, dearest brethren and longed-for, ever heartily farewell.