To explain to people the importance of having Him in their lives, Jesus used an analogy about the vine and the branches. (See John 15:1–8.) Jesus said, “I am the vine, you are the branches” (verse 5). He was very specific. He has given us a point of orientation in interpreting the whole picture. Jesus Himself is the vine.
For a vine to live and bear fruit, there must be sap—a source of nutrients that flows up from the roots, through the trunk, and into the branches. If the sap does not reach the branches, however, they will wither and fail to bear fruit. The key to the life of the vine is the sap, which represents the Holy Spirit. In Romans 8:10, Paul said,
If Christ be in you, the body is dead because of sin; but the Spirit is life because of righteousness. (kjv)
We experienced Christ’s death because of our sins. But, having experienced His death, we enter into His life because of His righteousness imputed to us through faith. (See Romans 6:6–8.) And, having His righteousness, we partake of His life. We partake of the life that flows from the roots, through the trunk of the vine, and into the branches. Paul told us in Romans 8:10 that the life is the Holy Spirit. The Spirit is life.