Eternal life. The term “eternal life” is commonly translated “everlasting life” or “life eternal”. The word “eternal” does not define the duration of the life, but it defines the character of the life. It couldn’t be the idea of “living forever” because even the unsaved live forever in eternal fire. It is a life of love, holiness, peace, and joy. Above all, eternal life is characterized by communion with the Father and the Son by the Holy Spirit; “And this is life eternal, that they might know thee the only true God, and Jesus Christ, whom thou hast sent” (John 17:3). Eternal life is the highest character of life that one can ever know, because it is the same life that the Father and Son enjoy together (1 John 1:3), and which had existed from eternity to eternity (John 1:2). In His ineffable grace, God in His eternal counsels purposed that this fellowship of the Father and the Son would be shared with the sons of men! We are brought into this fellowship through the gift of eternal life.
In scripture, eternal life is contrasted with new birth
. In the Old Testament times, God imparted Divine life through New birth, but Eternal life – a higher character of Divine life – was only possible after the cross, after the resurrection, and after the Spirit of God was sent down.
“In Him and in you”. The Apostle John writes of the Eternal life that was manifest in the Person of Christ on earth:
“That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked upon, and our hands have handled, of the Word of life; For the life was manifested, and we have seen it, and bear witness, and show unto you that eternal life, which was with the Father, and was manifested unto us; That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son Jesus Christ.” 1 John 1:1-3
God, willing to make Himself known as Father, sent the Son into the world. Here below, the Son made the Father perfectly known. For this reason He is called the “Word of God”, because He is the expression of who God is. John said of the Person of the Son, “in Him was life.” John and the other apostles had watched the Lord walking through this pathway, and they had seen a man living a lifestyle that was utterly beyond anything they had seen before. It was a life of love, holiness, peace, and joy; lived in the power of the Spirit of God, and full of the conscious enjoyment of the Father’s presence. The apostles had “heard”, “seen”, and actually “handled” the Person of Jesus, who was the perfect manifestation, or “Word” of Life. But then, by getting to know the Lord, and through enjoying communion with Him, they were able to share in that special fellowship. It was “out of this world” as to its character; therefore called “eternal” life. John writes to us that we might share in the enjoyment of that fellowship, with the Father, the Son, and all the other children in the Family of God, and that our joy might be full. In ch.2, John says that this “thing”, is “true in him and in you” (1 John 2:8). We now share that same eternal life! The Son “is eternal life” in His Person (1 John 5:20), and therefore “he that hath the Son hath life” (1 John 5:12). Christ has that life intrinsically in His Person, we have it in a derivative sense.
The Need for Eternal Life. The third chapter of John takes up man’s need, not only for New Birth, but also for Eternal Life. Man has not really lived, until he has been given eternal life. In John 3:12, the Lord said that He had been speaking of “earthly things” when He spoke of New birth. New birth was necessary for the earthly restoration of Israel, and it was contained in Old Testament prophecy (Jer. 31:33; Ezek. 11:19; 36:24-32; Hos. 6:2; and Isa. 44:2-3, etc.). Jesus went on to say that He had been sent from the Father to reveal heavenly blessings never known in the Old Testament. He went on to explain that these “heavenly things” (referred to as “Eternal life”), would be given to whoever believed on the “only-begotten” Son of God. It is really the possession of Eternal life that gives the believer assurance that his sins are gone, and puts him into communion with the Father and Son by the indwelling Spirit of God. It is all on the basis of the Son of man being “lifted-up” in death on the cross.
Resurrection Life, or Abundant Life, or Life in the Son.
Christ’s death and resurrection is what made it possible for us to have eternal life. This life is not a totally different life from the life we have by new birth. It can be thought of as an “upgraded life”. Similar to upgrading software from Version 1.0 to 2.0, Eternal life has all the characteristics of Divine life, but much, much more. The disciples received this life on resurrection day (John 20:22), and therefore we call it “Resurrection Life” 
. This life is of the highest
. It is beyond the tomb, and can never be touched by sin or death. John referred to it as “life in the Son” (1 John 5:11). It is called “Abundant Life” in John 10:10, where the aspect emphasized is the fullness of our enjoyment
of its characteristics and relationships on the other side of death.
Eternal life for the believer is to share the very life of the Son of God, to enjoy communion with Him and with the Father, to understand the things of God, and to walk in the enjoyment of it all in the power of the Holy Spirit.
Eternal life in Johannine and Pauline Writings. There are a few differences between eternal life in John’s ministry and Paul’s ministry. One is that John shows the character of the life in itself (“in the Son”), whereas Paul is occupied with the position of the believer, the place where we have that life (“in Christ”). Another difference is that John always refers to Eternal life as something that the believer possesses now on earth. Often, John will say; such and such a person “has eternal life”, present tense. Paul often presents it as a future thing to be enjoyed in heaven; and he will say “unto eternal life”, future tense.
The Present and Future Aspects of Eternal life. When eternal life is looked at as a present possession (usually in John’s writings), it is something that we enjoy now by the Holy Spirit, and it cannot be taken away (John 10:28). When eternal life is looked at as a future possession (usually in Paul’s writings), it is something we will enjoy when we get to heaven. Both are true! A nice illustration has been given for these two different aspects. In the old days of deep-sea diving, a diver would wear an iron helmet connected to an air-supply at the surface by a strong hose. A pump would flow fresh air from the surface down to where the diver was, perhaps hundreds of feet under water. The diver pictures the Christian, in our present life on earth. The air in the helmet is like Eternal life as a present possession. The Christian walks through an evil word, but he can still enjoy eternal life because he is connected to the mother ship. If he does not remain connected, he will begin to fade. Side note: this is why we need to “abide in the vine” (John 15). When the diver comes back to the surface, he takes off the iron helmet, and is greeted by a gust of cool, fresh air! This air is like Eternal life as future possession. It is the same air the diver was breathing when he was submerged, but now he is breathing his native environment! The same is true for us; we enjoy Eternal life now in a measure, but soon in its fullness when we are with the Lord!