John 15:17

These things I command you
The doctrines which Christ spake, as one having authority, concerning the vine and branches; his love to his disciples, in laying down his life for them, and in accounting and using them as friends, and not servants; in choosing, ordaining, and sending them forth, for the ends above mentioned; these were delivered by him with this view, to promote brotherly love among them: that ye love one another; this lay much upon his heart, he often mentions it; this is the third time it is expressed by him, in these his last discourses; and indeed, since he had declared such strong love and affection for them, it was but right and proper they should love one another; nor does anything more tend to increase mutual love among the saints, than the consideration of their common interest in the unchangeable love of their Lord.