"I am the true vine, and My Father is the vinedresser. Every branch in Me that does not bear fruit He takes away; and every branch that bears fruit He prunes, that it may bear more fruit.
You are already clean because of the word which I have spoken to you. Abide in Me, and I in you. As the branch cannot bear fruit of itself, unless it abides in the vine, neither can you, unless you abide in Me.
"I am the vine, you are the branches. He who abides in Me, and I in him, bears much fruit; for without Me you can do nothing.
If anyone does not abide in Me, he is cast out as a branch and is withered; and they gather them and throw them into the fire, and they are burned. If you abide in Me, and My words abide in you, you will ask what you desire, and it shall be done for you.

By this My Father is glorified, that you bear much fruit; so you will be My disciples. "As the Father loved Me, I also have loved you; abide in My love. If you keep My commandments, you will abide in My love, just as I have kept My Father's commandments and abide in His love.
"These things I have spoken to you, that My joy may remain in you, and that your joy may be full.
This is My commandment, that you love one another as I have loved you. Greater love has no one than this, than to lay down one's life for his friends.

These verses, we must carefully remember, contain a parable. In interpreting it we must not forget the rule which applies to all Christ's parables. The general lesson of each parable is the main thing to be noticed. The minor details must not be tortured and pressed to an excess, in order to extract a meaning from them. [Secondly parables are not doctrine, although they can illustrate such.]

We are meant to learn first, from these verses, that the union between Christ and believers is very close. He is "the Vine," and believers are "the branches." In themselves believers have no life, or strength, or spiritual power. All that they have comes from Christ. They are what they are, and feel what they feel, and do what they do, because they draw out of Jesus a continual supply of grace, help, and ability. Joined to the Lord by faith, and united in union with Him by the [Holy] Spirit, they stand, and walk, and continue, and run the Christian race. Ands every jot of good about them is drawn from their spiritual Head, Jesus Christ.

These verses are comfortable and instructive. Believers have no cause to despair of their own salvation, and to think they will never reach heaven. Let them consider that they are not left to themselves and their own strength. Their root is Christ, and all that there is in the root is for the benefit of the branches. Because He lives, they shall live also. Worldly people have no cause to wonder at the continuance and perseverance of believers. Weak as they are in themselves, their Root is in heaven, and never dies. "When I am weak," said Paul, "then am I strong." (2Corinthians 12:10.)

We are meant to learn, secondly, from these verses, that there are false Christians as well as true ones. There are "branches in the vine" which appear to be joined to the parent stem, and yet bear no fruit. There are men and women who appear to be members of Christ, and yet will prove finally to have had no vital union with Him. There are myriads of professing Christians in every Church whose union with Christ is only outward and formal. Some of them are joined to Christ by baptism and Church-membership. Some of them go even further than this, and are regular communicants and loud talkers about religion. But they all lack the one thing needful. Notwithstanding what church services they attend, they have no grace in their hearts, no faith, no inward work of the Holy Spirit. They are not one with Christ, and Christ in them. Their union with Him is only nominal, and not real. They have "a name to live," but in the sight of God they are dead. Christians of this stamp are aptly represented by branches in a vine which bear no fruit. Useless and unsightly, such branches are only fit to be cut off and burned. They draw nothing out of the parent stem, and make no return for the place they occupy. Just so will it be at the last day with false professors and nominal Christians. Their end, except they repent, will be destruction. They will be separated from the company of true believers, and cast out, as withered, useless branches, into everlasting fire. They will find at last, whatever they thought in this world, that there is a worm that never dies, and a fire that is not quenched.

We are meant to learn, thirdly, from these verses, that the fruits of the Spirit are the only satisfactory evidence of a man being a true Christian. The disciple that "abides in Christ," like a branch abiding in the vine, will always bear fruit.

He that would know what the word "fruit" means, need not wait long for an answer. Repentance toward God, faith toward our Lord Jesus Christ, holiness of life and conduct, these are what the New Testament calls "fruit." These are the distinguishing marks of the man who is a living branch of the true Vine. Where these things are wanting, it is pointless to talk of possessing dormant grace and spiritual life. Where there is no fruit there is no life; such a person is dead. "Fruit" is the only satisfactory evidence of saving union between Christ and our souls. Where there is no fruit of the Spirit to be seen, there has been no rebirth; the heart is dead. The Spirit of Life in Christ Jesus will always make Himself known in the daily conduct of those in whom He dwells. The Master Himself declares, "Every tree is known by his own fruit." (Luke 6:44.)

We are meant, lastly, to learn from these verses, that God will often increase the holiness of true Christians by His providential dealings with them. "Every branch," it is written, "that bears fruit He prunes, that it may bear more fruit."
The meaning of this language is clear and plain. Just as the vine-dresser prunes and cuts back the branches of a fruitful vine, in order to make them more fruitful, so does God purify and sanctify believers by the circumstances of life in which He places them.

JC Ryle Expository Thoughts on the Gospels: John's Gospel [with some slight changes to the language]