I AM drawn so strongly these days to John 15 where Jesus says,

Whoever remains in me and I in him will bear much fruit, because without me you can do nothing. (v. 5)

How can we ever grow in holiness if we do not remain in Him? Prayer is that which draws the sap of the Holy Spirit into our souls, causing the buds of holiness to spring forth. But they will only bloom if we nurture them in the will of God:

If you keep my commandments you will remain in my love. (v. 10)