I like the phrase "a sudden emergence of an entirely new and original element." We become partakers of the life of God suddenly! Through simple faith in Jesus Christ, the miracle of the new birth takes place in the spirit of the believer. Eternal life is a spiritual substance from heaven that is imparted in the spirit of a man. Eternal life is not simply life that goes on forever. It is true that the New Testament never forgets that God has promised men resurrection from the dead, but the essential of eternal life is not duration, it is quality. Eternal life is the injection into the realm of time of something of the realm of eternity. It is the coming into human life of something of the life of God.

Life As God Has It
God has given us a new quality of life in Christ. He has given us His own life, the very same life that raised Jesus from the dead (Ephesians 2:4-6). He has given us eternal life. God wants us to know that we have eternal life now. We are not trying to get it or some day in the sweet-by-and-by going to get it. We know we have a present possession we have eternal life. The gift of God is eternal life (Romans 6:23).

What a great gift God has given us in Christ! The Greek word in the New Testament for life or eternal life is zoe. This life is the primary purpose Jesus came. Jesus said, "I am come that you might have life, and that you might have it more abundantly," John 10:10.  This life is a spiritual substance that flows in heaven from the throne of God; it flows like a river (John 7:37-39). God is overflowing with this life.

You and I can have more and more of this life flowing in us. We can have this life in ever-increasing measures as we are filled with the Word of God and the Holy Spirit. We can walk in the light of this life and in the consciousness of what we have in Christ as we learn more and more of the "words of this life" (Acts 5:20). 

Eternal Life—Present Actual Possession
I Like W.E. Vine's definition of the word "zoe" (eternal life, everlasting life, or life).  It is life as a principle...life in the absolute sense, as God has it, that which the Father has in Himself and which He gave to the incarnate Son to have in Himself (John 5:26). It is what the Son manifested in the world (1 John 1:1,2). From this life man has become alienated through the fall and of this life men become partakers through faith in the Lord Jesus Christ, who becomes its author to all who trust in Him. The life He gives, He maintains. Eternal life is the present actual possession of the believer because of his relationship with Christ, and that it will one day extend its domain to the sphere of the body is assured by the resurrection of Christ.

Summary Points: But the essential of eternal life is not duration, it is quality.  God has given us a new quality of life in Christ.   This life is the primary purpose Jesus came.

Source: Taking Your Place In Christ by by Mark Hankins
Excerpt permission granted by MHM Publications