John Calvin Commentary John 15:4

"Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; so neither can ye, except ye abide in me." — John 15:4 (ASV)

Abide in Me. He again exhorts them to be earnest and careful in keeping the grace which they had received, for the carelessness of the flesh can never be sufficiently stirred. Indeed, Christ has no other object in view than to keep us

as a hen keeps her chickens under her wings,
(Matthew 23:37)

so that our indifference does not carry us away and make us fly to our destruction. To prove that He did not begin the work of our salvation only to leave it imperfect midway, He promises that His Spirit will always be efficacious in us, if we do not hinder Him.

Abide in Me, He says: for I am ready to abide in you. And again, He who abides in Me bears much fruit. By these words He declares that all who have a living root in Him are fruit-bearing branches.