John Calvin on John 15:6

6. If any one abide not in me. He again lays before them the punishment of ingratitude, and, by doing so, excites and urges them to perseverance. It is indeed the gift of God, but the exhortation to fear is not uncalled for, lest our flesh, through too great indulgence, should root us out.

He is cast out, and withered, like a branch. Those who are cut off from Christ are said to wither like a dead branch; because, as the commencement of strength is from him, so also is its uninterrupted continuance. Not that it ever happens that any one of the elect is dried up, but because there are many hypocrites who, in outward appearance, flourish and are green for a time, but who afterwards, when they ought to yield fruit, show the very opposite of that which the Lord expects and demands from his people. “Lesquels puls apres quand il faut rendre le fruict, monstrent tout le contraire de ce que le Seigneur attend et requicrt des siens.”

John 15:7-11

7. If you abide in me, and my words abide in you, you shall ask what you will, “Demandez tout ce que vous voudrez;” — “ask whatever you will.” and it shall be done for you. 8. In this my Father is glorified, that you bear much fruit, and become my disciples. 9. As the Father hath loved me, so have I loved you; abide in my love. 10. If you keep my commandments, you will abide in my love, as I also have kept my Father’s commandments, and abide in his love. 11. These things I have spoken to you, that my joy may abide in you, and that your joy may be full.