Thus this verse would be connected not directly with verse 13, but with the presumed consequence of the way of life legislated there. But is it right to proceed this way? Therefore the question is not at all superfluous: why did Saint Paul say this, or give his speech such a turn?
Saint Chrysostom understands these words not as expressing a general thought, but as covertly rebuking the bad condition of the Galatians. He does this to bring them to their senses and, by indicating its source in the heresy that had entered, to present the heresy itself in an unfavorable light.
Already under verse 13, on the words, "serve one another through love," he said: "The Apostle lets it be understood that the cause of their error was love of dispute, disagreements, love of rule, and pride. For the mother of heresies is the passion for ruling. By the words, 'serve one another,' he showed that the evil arose precisely from this vainglory and pride. Therefore he presents the corresponding remedy. Since, he says, you have divided among yourselves, desiring to rule one another, serve one another, and you will be united again. Yet he does not openly name their sin, but openly sets forth only the means of correction, so that from this they may learn their sin. It is like someone who, without directly saying to an immoral man that he is immoral, only exhorts him to chastity."
Saint Chrysostom carries the same thought under verse 15: "He did not state his thought here directly, lest he grieve them, although he knew that this was happening among them. He says the same thing, but with the appearance of some doubt. For he did not say, 'Since you bite one another,' nor did he later say directly, 'You will be destroyed by one another.' Such speech belongs to one who only frightens and advises, not to one who condemns. Yet he used the most striking and sharp words. He did not merely say, 'bite,' which an irritated man sometimes does, but added, 'devour,' which belongs to one hardened in malice. The one who bites only satisfies the passion of anger, but the one who devours reveals in himself the extreme degree of savagery. Yet he means not bodily biting and devouring, but things far worse. For one who devours a man's flesh does not do as much harm as one who bites his soul. As much as the soul is more precious than the body, so much more grievous is the evil inflicted on it. 'Take heed that you are not consumed by one another.' Since deceivers and plotters come in order to destroy others, see to it, he says, that the matter does not reach even to you. Divisions and strife corrupt and devour both those who receive them and those who sow them. They consume everything even more than a moth."
Blessed Jerome sets forth another thought: "This passage must be interpreted so that Saint Paul does not seem suddenly to pass to unexpected instructions standing outside all connection with the content of the Epistle. He wishes to say to them: having received freedom from the Law, serve one another through love. This will be the best fulfillment of the Law itself. But if you remain with the Law, then you will already have to accept everything, including eye for eye. Following this, you will bite and devour one another. Beware. This is where the Law will lead you. You will be destroyed by one another." This is not word for word.