Synonyms: rebirth, new birth,“born again”, renewal, re-creation.
Related ideas: baptism, forgiveness, the gift of the Holy Spirit, resurrection, spiritual death, eternal life.
Definitions: Regeneration is being “born again” (spiritually of course, not bodily). The “old person” (the condemned sinner) is no more, and a “new person” (the saint) is re-createdin Christ.
1Peter 1:23-25 “Born again, not of seed which perishes, but which is imperishable, by the living and abiding word of God.”
Romans 12:1-2 “Be transformed by the renewing of your mind...”
Regeneration and the Resurrection
1Peter 1:3-4 “...born again to a living hope through the resurrection of Jesus Christ from the dead, to obtain an inheritance which is imperishable and undefiled and will not fade away, reserved in heaven for you.”
2Corinthians 5:15-17 “...he died for all... and rose again on their behalf... therefore if any person is in Christ he is a new creature. The old things have passed away, behold all things have become new.”
Regeneration and baptism
John 3:1-8 esp v.5 “...unless one is born of water and the Spirit he cannot enter into the kingdom of God.”
Romans 6:3-6 “baptized into his death ...buried with him through baptism... so that we... might walk in newness of life.”
Ephesians 5:26, Titus 3:5, Revelation 1:5 “...by the washing of water with the word... by the washing of regeneration... [Jesus] washed us from our sins in his blood.”
Baptism does not regenerate a person. Baptism is certainly essential to regeneration, because one is “baptized into Christ... into his death”. However it is God, the Holy Spirit, who regenerates a person by means of Christ's death and resurrection.
Regeneration and the Holy Spirit
Titus 3:5-6 “...and renewal of the Holy Spirit, whom he poured out on us richly through Jesus Christ our Saviour.”
Romans 8:2 “...the law of the Spirit of life in Christ Jesus has set you free from the law of sin and death.”
Comment: “Regeneration” is a big word for renewal or rebirth. Likewise being “regenerated” is simply being “born again”. Rebirth is important in the doctrine of Christ. It is bringing back to life of a person who is spiritually dead —dead in sin. It is not merely a spiritual resuscitation but a complete new start, a new genesis for the person. We may think of regeneration as a precursor of the resurrection at the last day, when begins a new life without end in heaven. We may consider it so, because the Holy Spirit, given at our rebirth, is a guarantee or down payment of that eternal life.