How did humanity become children of God once more?

The genealogy of Christ tell us that Christ was “… the son of Enoch, the son of Seth, the son of Adam, the son of God” (Luke 3:23–38). Since Adam lost this grace, how was it restored to us again? As Christ ascended into the heavens, He sent us His Holy Spirit who takes of what is His and declares it to us (John 16:14). What does the Holy Spirit take and declare to us? He takes Christ’s salvific works and presents them to us.

In the waters of baptism, the Holy Spirit buries us with Christ and raises us also together with Him, so that we may come out of baptism as members in the body of the risen Christ, which never gets old but continues to grow unceasingly in the new life.

In this way, our unity with Christ is achieved and we become children of God. Through the Only Begotten Son, we become children with Him by adoption, not by nature but by God’s free grace. This is what the Apostles meant by saying, “Not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration, and renewing of the Holy Spirit” (Titus 3:5), and “Blessed be the God and Father of our Lord Jesus Christ, who according to His abundant mercy has begotten us again to a living hope through the resurrection of Jesus Christ from the dead, to an inheritance incorruptible, and undefiled, and that does not fade away, reserved in heaven for you” (1 Pet. 1:3–4).

Christ Himself referred to this in His conversation with Nicodemus: “Most assuredly, I say to you, unless one is born of water and the Spirit, he cannot enter the kingdom of God” (John 3:5). Nicodemus, the teacher of Israel, could not understand, because he had not yet realized that the same Jesus, with whom he was talking was bringing believers to Himself in baptism by the Holy Spirit, so as to grant them His risen life, which is the gift of the new spiritual birth (John 3:9–21).