Matthew 12:30

After that third reply, here follows a fourth, "He that is not with me is against me."

Wherein He shews how far He is from having borrowed any power from the Devil; teaching us how great the danger to think amiss of Him, not to be with Whom, is the same as to be against Him.

But let none think that this is said of heretics and schismatics; though we may apply it besides to such; but it is shewn by the context to refer to the Devil; in that the works of the Saviour cannot be compared with the works of Beelzebub. He seeks to hold men's souls in captivity, the Lord to set them free; he preaches idols, the Lord the knowledge of the true God; he draws men to sin, the Lord calls them back to virtues. How then can these have agreement together, whose works are so opposite?

Therefore whoso gathereth not with me, nor is with me, may not be compared together with me, that with me he should cast out daemons, but rather seeks to scatter what is mine. But tell me; If you were to have fought together with some one, and he should not be willing to come to your aid, is he not therefore against you? The Lord also Himself said in another place, "He that is not against you is for you." [Luke 9:50] To which that which is here said is not contrary. For here He is speaking of the Devil who is our adversary, there of some man who was on their side, of whom it is, said, "We saw one casting out daemons in thy name." Here He seems to allude to the Jews, classing them with the Devil; for they were against Him, and scattered what He would gather. But it is fair to allow that He spoke this of Himself; for He was against the Devil, and scattered abroad the things of the Devil.

6. The spouse of Christ cannot be adulterous; she is uncorrupted and pure. She knows one home; she guards with chaste modesty the sanctity of one couch. She keeps us for God. She appoints the sons whom she has born for the kingdom. Whoever is separated from the Church and is joined to an adulteress, is separated from the promises of the Church; nor can he who forsakes the Church of Christ attain to the rewards of Christ. He is a stranger; he is profane; he is an enemy. He can no longer have God for his Father, who has not the Church for his mother. If any one could escape who was outside the ark of Noah, then he also may escape who shall be outside of the Church. …

28. What wonder is it, beloved brethren, if such is the prayer which God taught, seeing that He condensed in His teaching all our prayer in one saving sentence? This had already been before foretold by Isaiah the prophet, when, being filled with the Holy Spirit, he spoke of the majesty and loving-kindness of God, “consummating and shortening His word,” He says, “in righteousness, because a shortened word will the Lord make in the whole earth.” For when the Word of God, our Lord Jesus Christ, came unto all, and gathering alike the learned and unlearned, published to every sex and every age the precepts of salvation, He made a large compendium of His precepts, that the memory of the scholars might not be burdened in the celestial learning, but might quickly learn what was necessary to a simple faith. …

In Ecclesiasticus, in Solomon: “He that cleaveth firewood shall be endangered by it if the iron shall fall off.” Also in Exodus: “In one house shall it be eaten: ye shall not cast forth the flesh abroad out of the house.” Also in the cxxxiid Psalm: “Behold how good and how pleasant a thing it is that brethren should dwell in unity!” Also in the Gospel according to Matthew: “He that is not with me is against me; and he that gathereth not with me scattereth.” Also in the first Epistle of Paul to the Corinthians: “But I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all say the same thing, and that there be no schisms among you; but that ye be all joined together in the same mind and in the same opinion.” Also in the sixty-seventh Psalm: “God, who maketh men to dwell with one mind in a house.”

Secundinus of Cedias said: Since our Lord Christ says, “He who is not with me is against me;” and John the apostle calls those who depart from the Church Antichrists, undoubtedly enemies of Christ, any such as are called Antichrists cannot minister the grace of saving baptism. And therefore I think that those who flee from the snares of the heretics to the Church must be baptized by us, who are called friends of God, of His condescension.

Another Secundinus of Carpi said: Are heretics Christians or not? If they are Christians, why are they not in the Church of God? If they are not Christians, how come they to make Christians? Or whither will tend the Lord’s discourse, when He says, “He that is not with me is against me, and he who gathereth not with me scattereth?” Whence it appears plain that upon strange children, and on the offspring of Antichrist, the Holy Ghost cannot descend only by imposition of hands, since it is manifest that heretics have not baptism.

LVI . For this is that which our Lord taught us when we pray to say to His Father, “Thy will be done, as in heaven, so upon earth;” that as the heavenly natures of the incorporeal powers do all glorify God with one consent, so also upon earth all men with one mouth and one purpose may glorify the only, the one, and the true God, by Christ His only-begotten. It is therefore His will that men should praise Him with unanimity, and adore Him with one consent. …

LIX . When thou instructest the people, O bishop, command and exhort them to come constantly to church morning and evening every day, and by no means to forsake it on any account, but to assemble together continually; neither to diminish the Church by withdrawing themselves, and causing the body of Christ to be without its member. For it is not only spoken concerning the priests, but let every one of the laity hearken to it as concerning himself, considering that it is said by the Lord: “He that is not with me is against me, and he that gathereth not with me scattereth abroad.” Do not you therefore scatter yourselves abroad, who are the members of Christ, by not assembling together, since you have Christ your head, according to His promise, present, and communicating to you. …

6. Hence we understand both that the good shepherds are those who seek not their own, but the things of Jesus Christ, and that the good sheep, though imitating the works of the good shepherds by whose ministry they have been gathered together, do not place their hope in them, but rather in the Lord, by Whose blood they are redeemed; so that when they may happen to be placed under bad shepherds, preaching Christ’s doctrine and doing their own evil works, they will do what they teach, but will not do what they do, and will not, on account of these sons of wickedness, forsake the pastures of the one true Church. …

16. That the whole ark together is finished in a cubit above; as the Church, the body of Christ gathered into unity, is raised to perfection. So Christ says in the Gospel: "He that gathereth not with me, scattereth." That the entrance is on the side; as no man enters the Church except by the sacrament of the remission of sins which flowed from Christ’s opened side. That the lower spaces of the ark are divided into two and three chambers: as the multitude of all nations in the Church is divided into two, as circumcised and uncircumcised; or into three, as descended from the three sons of Noah. And these parts of the ark are called lower, because in this earthly state there is a difference of races, and above we are completed in one. Above there is no diversity; for Christ is all and in all, finishing us, as it were, in one cubit above with heavenly unity.

Chapter 7. 9. For, in the next place, that I may not seem to rest on mere human arguments, since there is so much obscurity in this question, that in earlier ages of the Church, before the schism of Donatus, it has caused men of great weight, and even our fathers, the bishops, whose hearts were full of charity, so to dispute and doubt among themselves, saving always the peace of the Church, that the several statutes of their Councils in their different districts long varied from each other, till at length the most wholesome opinion was established, to the removal of all doubts, by a plenary Council of the whole world: I therefore bring forward from the gospel clear proofs, by which I propose, with God’s help, to prove how rightly and truly in the sight of God it has been determined, that in the case of every schismatic and heretic, the wound which caused his separation should be cured by …

17. Now, therefore, the question is, how could men of the party of the devil belong to the Church, which has no spot, or wrinkle, or any such thing, of which also it is said, "My dove is one?" But if they cannot, it is clear that she groans among those who are not of her, some treacherously laying wait within, some barking at her gate without. Such men, however, even within, both receive baptism, and possess it, and transmit it holy in itself; nor is it in any way defiled by their wickedness, in which they persevere even to the end. …

Chapter 17. 25. "Can the power of baptism," says Cyprian, "be greater or better than confession? than martyrdom? that a man should confess Christ before men, and be baptized in his own blood? And yet," he goes on to say, "neither does this baptism profit the heretic, even though for confessing Christ he be put to death outside the Church." This is most true; for, by being put to death outside the Church, he is proved not to have had charity, of which the apostle says, "Though I give my body to be burned, and have not charity, it profiteth me nothing." But if martyrdom is of no avail for this reason, because it has not charity, neither does it profit those who, as Paul says, and Cyprian further sets forth, are living within the Church without charity in envy and malice; and yet they can both receive and transmit true baptism. …