Hebrews 13:1

The design of Christ in giving himself for us is that he may purchase to himself a peculiar people, zealous of good works. Now the apostle calls the believing Hebrews to the performance of many excellent duties, in which it becomes Christians to excel. I. To brotherly love (Heb 13:1), by which he does not only mean a general affection to all men, as our brethren by nature, all made of the same blood, nor that more limited affection which is due to those who are of the same immediate parents, but that special and spiritual affection which ought to exist among the children of God. 1. It is here supposed that the Hebrews had this love one for another. Though, at this time, that nation was miserably divided and distracted among themselves, both about matters of religion and the civil state, yet there was true brotherly love left among those of them who believed on Christ; and this appeared in a very eminent manner presently after the shedding forth of the Holy Ghost, when they had all things common, and sold their possessions to make a general fund of subsistence to their brethren. The spirit of Christianity is a spirit of love. Faith works by love. The true religion is the strongest bond of friendship; if it be not so, it has its name for nothing. 2.

— Matthew Henry's Concise Commentary (public domain)