Jesus answered him, "Most assuredly, I tell you, unless one is born anew,{The word translated "anew" here and in John 3:7 (anothen) also means "again" and "from above".} he can't see the Kingdom of God."
"If the kingdom does not dawn until the end of the age [and it will], then of course one cannot enter it before it comes. Predominant religious thought in Jesus’ day affirmed that all Jews would be admitted to that kingdom apart from those guilty of deliberate apostasy or extraordinary wickedness (e.g., Mishnah Sanhedrin John 10:1). But here was Jesus telling Nicodemus, a respected and conscientious member not only of Israel but of the Sanhedrin, that he cannot enter the kingdom unless he is born again. . . . The coming of the kingdom at the end can be described as the ’regeneration’ of the world (Matthew 19:28, NIV ’renewal’), but here what is required is the regeneration of the individual before the end of the world and in order to enter the kingdom." [Note: Carson, pp. 188-89.] 