I am the vine, ye are the branches: He that abideth in me, and I in him, the same bringeth forth much fruit: for without me ye can do nothing.
Christ Himself is the vine, while believers are the vine branches. It is not a question of the branch living its life for the vine, but simply of letting the life of the vine flow out through the branches. A vine branch has one great purpose – to bear fruit. The vine branch can only bear fruit, if it abides in the vine.