What Nicodemus needs, and what you and I need, is not religion but life. The point of referring to new birth is that birth brings a new life into the world. In one sense, of course, Nicodemus is alive. He is breathing, thinking, feeling, acting. He is a human created in God’s image. But evidently, Jesus thinks he’s dead. There is no spiritual life in Nicodemus. Spiritually he is unborn. He needs life, not more religious activities or more religious zeal. He has plenty of that. John Piper

The Bible describes being born again as…

• A permanent, unalterable change in someone at his or her deepest level.
• A deep work in the heart, our total inner self, so that a new life flows from a new heart empowered by the Holy Spirit, just as Jesus explained to Nicodemus (Deut 30:6; Jer 24:7; 31:31; Ezek 11:19-20; 36:26-27)
• A gift of grace (Titus 3:5)
• A work of the Holy Spirit (John 3:5-8)

Without being born again there is no possibility of eternal life in God’s kingdom. Have you been born again?