John Calvin Commentary John 15:11

"These things have I spoken unto you, that my joy may be in you, and [that] your joy may be made full." — John 15:11 (ASV)

These things I have spoken to you. He adds that His love is far from being unknown to the godly, but it is perceived by faith, so that they enjoy blessed peace of conscience. For the joy He mentions springs from that peace with God which is possessed by all who have been justified by free grace. Therefore, whenever God’s fatherly love towards us is preached, let us know that we are given ground for true joy, so that, with peaceable consciences, we may be certain of our salvation.

My joy and your joy. It is called Christ’s joy and our joy in various respects. It is Christ’s because it is given to us by Him, for He is both the Author and the Cause of it.

I say that He is the Cause of it, because we were freed from guilt when the chastisement of our peace was laid on Him (Isaiah 53:5).

I also call Him the Author of it, because by His Spirit He drives away dread and anxiety in our hearts, and then arises that calm cheerfulness. It is said to be ours for a different reason; because we enjoy it since it has been given to us. Now since Christ declares that He spoke these things, that the disciples might have joy, we conclude from these words that all who have duly profited by this sermon have something on which they can rest.

That my joy may abide in you. By the word abide He means that it is not a fleeting or temporary joy of which He speaks, but a joy which never fails or passes away. Let us therefore learn that we ought to seek in the doctrine of Christ the assurance of salvation, which retains its vigor both in life and in death.

That your joy may be full. He adds that this joy will be solid and full; not that believers will be entirely free from all sadness, but that the ground for joy will be far greater, so that no dread, no anxiety, no grief, will swallow them up. For those to whom it has been given to glory in Christ will not be prevented, either by life, or by death, or by any distresses, from bidding defiance to sadness.