How do we know that spiritual birth is necessary for salvation?

The concept of spiritual birth is supported by Scripture, particularly when Jesus tells Nicodemus in John 3:3 that one must be born again to see the kingdom of God. This rebirth signifies a new identity in Christ, where believers are transformed from the inside out. Paul reinforces this in Galatians 3:26, stating that those who believe in Christ become children of God through faith. This spiritual rebirth is not something we achieve by our own merits but is a gracious act of God that imbues believers with a new heart capable of true faith and obedience.