"Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God." (John 3:3)
The vital doctrine of regeneration has been applicable in all ages, for man by nature is a lost sinner and must be spiritually reborn through faith in God and His promises to be saved. This truth appears in the Old Testament, for example, in David's prayer: "Create in me a clean heart, O God; and renew a right spirit within me" (Psalm 51:10).
It is emphasized more clearly and explicitly in the New Testament. "Not by works of righteousness which we have done, but according to his mercy he saved us, by the washing of regeneration, and renewing of the Holy Ghost; Which he shed on us abundantly through Jesus Christ our Saviour" (Titus 3:5-6). "Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever" (1 Peter 1:23).
Note that this spiritual birth is produced only through the eternal Word of God. "According to his abundant mercy," the Lord "hath begotten us again unto a lively hope by the resurrection of Jesus Christ from the dead, To an inheritance incorruptible, and undefiled, and that fadeth not away, reserved in heaven for you" (1 Peter 1:3-4).
To be raised from spiritual death in sin to eternal life in Christ is a true miracle, as much so as the physical resurrection of Christ Himself, or even as the very creation of the world. "For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ" (2 Corinthians 4:6).
"Therefore if any man be in Christ, he is a new |creation|: old things are passed away; behold, all things are become new" (2 Corinthians 5:17). HMM