How do we know that being born again is essential?

In John 3:3, Jesus declares, 'Except a man be born again, he cannot see the kingdom of God.' This frames the necessity of spiritual rebirth through the Holy Spirit for anyone hoping to enter God's eternal kingdom. The new birth aligns with the larger theological context of salvation in the Reformed tradition, where regeneration is a work of divine grace, setting apart the believer from their natural state of sinfulness. Furthermore, the acknowledgment of being a sinner before a holy God is the first step towards repentance and faith, a vital part of the conversion experience, highlighting that all must confront their sinful condition to be made alive in Christ (Ephesians 2:1-5).