Jesus taught Nicodemus that being born again means experiencing a complete spiritual transformation through God's power. This new birth involves being cleansed from sin (born of water) and receiving the Holy Spirit (born of Spirit), which changes us from the inside out. Unlike our human attempts at self-improvement, the new birth is God's work that gives us a fresh start, forgives our sins, and transforms our nature. This spiritual rebirth is necessary for everyone—regardless of background or status—to enter God's kingdom and experience relationship with Him both now and eternally.