William Burkitt on John 15:10

Christ had told his disciples in the foregoing verse, that he had loved them, even as the Father had loved him; that is, with an eternal love, with a real and operative love, with an immutable and constant love.

In this verse he directs them how they may continue in the sense of his love; namely, by their constant obedience to his commands, as his obedience to his Father's commands had secured him a continuance in his Father's love; If ye keep my commandments, ye shall abide in my love: that is, in the sense of my love, and under the sweet apprehensions of it.

Learn hence, That as our obedience to Christ is the best evidence of our love to him, so is it the best mean to preserve and keep us in the sense and assurance of his love to us.