In this passage, a man named Nicodemus came one night to visit Jesus. Nicodemus was both a Pharisee and a member of the Jewish ruling council. This meant that he belonged to the Sanhedrin, the council of seventy men charged with overseeing the religious affairs of the Jewish people. Nicodemus recognized Jesus as a teacher, a Rabbi, and as One who performed miraculous signs.
For his part, Jesus saw that even with all of his religious credentials, Nicodemus did not know God. And so Jesus said to him, "Very truly I tell you, no one can see the kingdom of God unless they are born again." Understanding the meaning and usages of the adverb "again," anothen provides us with a window into the meaning of Jesus' words. First, anothen can mean "a second time." This was Nicodemus's understanding. Second, anothen speaks of something "radically new" or "a new beginning." Third, anothen can mean "from above."
In combining these ideas, we find that the new birth is both radically new and that it comes down from above. In what follows, Jesus makes it clear that the new birth originates with the Spirit. Without the Spirit, there is no new birth.
John Wesley, the founder of the Methodist movement was once asked, "Why do you preach so often on 'you must be born again?'" He replied, "Because--you must be born again!" Have you been born again?