William Burkitt on John 15:13

Here our Saviour gives his disciples an evidence of the greatness of his love unto them; namely, in his readiness to lay down his life for them, which is the highest expression of love to our dearest friends, because life is the greatest earthly blessing.

Learn hence, That Christ's love, in laying down his life for his people, was a matchless love; for whilst they were enemies to him, he had a friendly respect for them; and never ceased till he had brought them into a covenant of friendship with himself.