What does the term 'spiritual birth' mean in Christianity?

Spiritual birth, often termed as being 'born again,' signifies the moment when the Holy Spirit imparts new life to an individual who was previously dead in sin. This concept is pivotal in Christian theology, as articulated in John 3:5, where Jesus explains that one must be born of water and the Spirit to enter the kingdom of God. Just as Jonah's experience illustrated his renewal and subsequent obedience, spiritual birth entails a fundamental change in a person's nature, fostering a desire to follow Christ and respond to His calling. It's God's initiative, as Ephesians 2:5 declares: 'Even when we were dead in trespasses, made us alive together with Christ.'