ETERNAL - "without beginning or end; existing throughout all time; everlasting."
EVERLASTING - "never coming to an end; lasting forever; eternal."
While Webster does use the words as interchangeable, there is a slight difference. Something that is eternal, such as God, has no beginning; He has always existed, and hence, His name is "I AM!" On the other hand, something that is everlasting, possibly had a beginning in time. For example, the Man called Jesus, began His earthly life when He was born of the virgin Mary. His human life had a beginning, but we know that, even though He was crucified and buried, He rose from the dead, never to die again! Peter wrote: "For so an entrance shall be ministered unto you abundantly into the everlasting kingdom of our Lord and Saviour Jesus Christ" (1 Pet. 1:11).
But in the case of Jesus, the Bible declares Him to be God (Jn. 1:1, 14)! And as God, He is also eternal. When believers speak of the Incarnation of Christ, we are declaring that the eternal God sent His eternal Son to become a human being. John wrote: "That whosoever believeth in Him should not perish, but have eternal life. For God so loved the world, that He gave His only begotten Son, that whosoever believeth in Him should not perish, but have everlasting life. For God sent not His Son into the world to condemn the world; but that the world through Him might be saved. He that believeth on Him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God" (Jn. 3:15-18).
The words "eternal life" and "everlasting life," appear a total of thirty-seven times in the New Testament! The born again believer possesses both! How is it that we have both everlasting life and eternal life? The answer lies in the fact that we are baptized into Him, that is, the Holy Spirit places us into the Son of God; hence, we are partakers of His eternal life (Rom. 6:3; 1 Cor. 12:13; Gal. 3:27; etc.). Because we are born again, that is, we have the eternal Spirit of God living within us from the moment we accept Jesus as our Lord, we also are partakers of our own everlasting life! We will live forever with Christ!
What God has begun (Phil. 1:6), and what the Spirit has sealed (Eph. 1:13; 4:30),
Jesus will keep with Him forever (1 Thes. 4:17)!