John 15:12

This is my commandment This I especially enjoin you, whether as apostles or private Christians; that ye love one another Cordially and constantly; even, if it be possible, with as great fervency and constancy, as I have loved you So as to be ready to sacrifice your lives for each other, as I expose and give up mine for you. It is remarkable, that no one duty is more frequently inculcated, or more pathetically urged upon his disciples, by our Lord, than that of mutual love. This is my commandment, he says, as if it were the most necessary of all the commandments. The reason might be, 1st, That as under the law, the prohibition of idolatry was the commandment more insisted on than any other, because God foresaw the people would be prone to that sin; so Christ, foreseeing that the Christian Church would be addicted to uncharitable contentions and divisions, strife and animosity, thought proper to lay the greatest stress upon this precept. 2d, Mutual love among Christians is a duty which both includes many other duties, and has a good influence upon all: and to this duty, Christ's love to us all should at once direct, animate, and urge us; he having thereby both shown us our duty in this respect, and laid us under the most powerful obligations to perform it. Add to this, that our Lord was thus earnest in pressing his disciples to the duty of mutual love, not only because it was the great design of his gospel to promote it, but because this virtue exercised by his apostles and first disciples among themselves, and toward all mankind, would be one great means of making their preaching successful; just as Christ's immense love to men will always have a great influence in drawing them to him.