Many people wrongly think that there was one saving message for OT people, another saving message for people at the time of Christ, and yet another saving message for people after the church was born. But the Lord made clear that the message He preached is the same message by which Abraham was saved (John 8:56) and by which anyone in His day, still pre-cross and pre-church, could be saved (John 5:39-40).
Jesus said, “I am the light of the world” (John 8:12; 9:5). Light reveals. He is the one who reveals God and God’s truth to us. Of special importance was Him revealing God’s truth about everlasting life (John 6:68).
The Lord Jesus is God’s greatest evangelist, and He told us what people must do to be saved during every age.
Zane Hodges wrote a booklet entitled, Jesus, God’s Prophet. He showed that all NT doctrine found in the epistles flows directly from the teachings of the Lord Jesus. That is true of the doctrine of salvation as well.
John 3:16 is still in effect today. So are the scores of verses in John’s Gospel where the Lord Jesus said that whoever believes in Him has everlasting life, will never perish, will never hunger or thirst, will never die spiritually, will never be cast out, and so forth.
Whatever the epistles teach, they do not contradict the words of the Lord Jesus Christ.
Paul tells us in Galatians that he received his gospel directly from the Lord Jesus (Gal 1:12). His was not some new message. His was the same message that Jesus preached.
The very last book of the Bible, Revelation, probably written in AD 70, but possibly as late as AD 95, gives the same saving message as John 4:10-14. See Rev 22:17. The water of life in John 4 is the same saving message as the water of life in Rev 22:17. The message did not change.
Jesus is much more than our Savior. He is our Lord. He is our King. He is our soon-returning Judge. He is also our Teacher. He is our Light. He is our life.
Morris writes concerning Jesus’ statement, “I am the way, the truth, and the life” (John 14:6): “the triple expression emphasizing the many-sidedness of the saving work” (John, pp. 569-70).
The One who is “the truth” is utterly dependable. When He says that whoever believes in Him will never perish, but has everlasting life, we can and should believe Him. Indeed, Jesus is the only way. Man-made evangelistic messages have no power to save. Only the message that Jesus gave us is the living water that springs up into everlasting life (John 4:14).
The Truth was and is the greatest evangelist of all time. We should believe and proclaim the message of life that He Himself gave us.