Both Jesus and Apostle Paul speak of regeneration that results in privileges of inheritance found only in adoption (John 1:9-13; Tit 3:4-7). What is adoption and how are regeneration and adoption related?

Adoption is the legal term that validates the act of a person who voluntarily brings a person of another family into their own and entitles them to the rights and privileges of a biological son or daughter.

In the Bible, the concept of adoption existed before the New Testament's introduction of regeneration.

Throughout the Old Testament, there is no Hebrew word for any aspect of adoption, and it was not a practice of Israelites. This was in part because Mosaic legislation required a man to remarry his brother's widow, and property was to be maintained within the tribe (Lev 25:23-34; Num 27:8-11; Jer 32:6-15).

However, adoption during this time was practiced by foreigners or by Jews influenced by foreign customs. For example, Pharaoh's daughter adopted Moses (Ex 2:10).

In instances of covenantal inheritance, there were inferences of adoption with the identification of sonship which designated the heirs (Gen 48:5; Ex 4:22-23; Hos 11:1). In most biblical references, adoption as a covenantal concept applied to a group of people, not to individuals.

In the first century A.D., Roman customs had a great influence on Jewish family life. In regard to adoption, Roman law viewed the adopted one as being born again into the new family and in essence a new creature. This legal concept was the analogy that Paul used to describe the relationship of a Believer to God.

With a view towards the legal meaning of adoption, Paul grieves for the nation of Israel for their arrogant attitude of being God's elect; the nation presumed their adoption through covenant promise by claiming to be descendants of Jacob or Abraham (Rom 9:3-7). The nation of Israel forgot that they were chosen by God's sovereign mercy in keeping with His promise to Abraham, and they did not understand who really belonged to Israel (Rom 9:4).

In contrast to physical descendants, the inheritance is for those of faith as symbolized by God's promise of a child to Abraham (Gal 4:28-29; Rom 9:7-9); Paul understood Believers to be metaphorically the children of the promise and the true offspring of Abraham.

To the saints in Ephesus, Paul affirmed that Believers were predestined to adoption as God's sons through Jesus Christ as a loving sovereign act of God (Eph 1:3-8).

To the Galatian Believer, Paul asserts that the Holy Spirit was sent into their hearts, because they were adopted as the sons of God (Gal 4:1-7). Regeneration is what enables a Believer to cry out "God, Father."

Adoption and regeneration are God's sovereign acts of committing Himself to Believers. They also represent an affirmation to Believers of their trust in God which continues to grow out of His Fatherhood (Rom 8:14-17), not only of the present, but of the future hope still to be fulfilled (Rom 8:23).

It can be said that regeneration validates the Believer's legal adoption by God.

Paul sees Believers as sons of Abraham (Gal 3:7, 29) and co-heirs with Christ (Rom 8:17).

Jesus sees Believers as sons of the resurrection (Luke 20:36; Mark 12:25; Matt 22:30), sons of the kingdom (Matt 13:38) and sons of light (John 12:36). Most significant is that Jesus is not ashamed to call Believers "brothers" (Heb 2:11).

How is regeneration related to adoption?

Adoption establishes a legal relationship and rights of inheritance and occurs before regeneration (Gal 4:5-6).

Regeneration changes the origin of birth and establishes a natural and holy relationship to God.