Adoption, as taught in the Bible, is one of the transformative events which take place when a person trusts Jesus Christ as their Saviour. Particularly in Ephesians 1:5, adoption is presented as the crowning accomplishment of God in respect of those who believe. Together these events precipitate a new and permanent standing before God which is then expressed in practical terms through a profound change of life.
Becoming part of God’s family
To understand the true meaning and significance of adoption, we must first consider the broader picture of what happens when a person trusts Jesus Christ as their Saviour. First, that person becomes part of the family of God, not by adoption, but by new birth (1 Peter 1:23 - 2:1). In creation, God imparted life through the Holy Spirit (Genesis 1:2) and through His spoken word (Genesis 1:3). Similarly, in salvation God uses these same agencies to impart life of a different kind - ‘eternal’ or ‘abundant’ life. This results in a second birth, through which a person becomes a child in the family of God.
A host of blessings flow from this new standing; a person is brought near to God as one of His children and privileged to share with God as one of His heirs. It’s in this context that we need to consider adoption; the means through which God makes a person not only His child, but also His son and heir. The Greek word for adoption (huiothesia) means ‘son placing’ and describes how, on conversion, and regardless of social distinctions or gender, God brings every Christian into a position of unparalleled honour as “sons of God by faith in Jesus Christ” (Galatians 3:26).
What it means to be a son
In the Bible, the terms ‘male-child’ and ‘son’ are not used interchangeably as they are today. The title of son is reserved for mature male children and describes a position into which they are placed when they come of age. An example of this is the Bar Mitzvah celebration, still observed today by Orthodox and Reformed Jews to mark the beginning of adulthood. Only when a son has attained this crucial level of maturity is he able to act as a representative of his father. This representation is one of the main ideas which the Bible links with son-ship. For instance, in the parable of the vineyard the landlord’s son is sent as the ultimate representative who is able to act with the full authority of his father in confronting the negligent tenants of the property (Matthew 21:33-43).
Mere maturity alone however, is not enough to adequately represent a father; the son must also display a similarity of character and behaviour.
Consider the cultural context of the New Testament; sons were defined by their fathers, being educated and trained at home to carry on in the same occupation (even the Lord Jesus became a carpenter, because His legal father Joseph was a carpenter). The concept that sons closely resemble their fathers was so embedded in New Testament culture that it even gave rise to figures of speech such as “son of consolation” (Acts 4:36) and “sons of light” (1 Thessalonians 5:5, ESV).
Furthermore, a son can take possession of that which belongs to them by birth right; their inheritance. Both child and son are heirs with the same inheritance (Galatians 4:1), but the child is not entrusted with that inheritance in practical terms until he becomes a mature son. At that point he possesses what belongs to his father (see Luke 15:31) and acts with authority as the delegate of his father over the household (Galatians 4:1).
All of this background is essential to understanding just how significant it is when God calls anyone His son. An Old Testament example is Israel, who collectively became God’s son (Exodus 4:22, Romans 9:4) and as such were uniquely called to know God and to represent Him among the nations. Later the term is applied to kings and rulers, as those who God had appointed to rule over His creation and to represent Him. Unsurprisingly, both Israel nationally and these rulers individually failed to live up to their high calling.
Against the background of failing sons God then introduces us to His perfect Son, the Lord Jesus Christ, who uniquely is described as theSon of God. As the perfect son He represents His Father in the fullest sense, so much so that whoever encounters Him has “seen the Father” (John 14:9). He also fully possesses His inheritance, as the Father has placed “all things…under Him” (1 Corinthians 15:27).
What is most remarkable however, is the fact that Christ’s perfect son-ship has not only been exhibited in heaven, but in the same earth we inhabit when the Son of God became a real man (Galatians 4:4). He lived under a system of law imposed temporarily on Israel to show them the standards and character of the God they served. Even though that law only revealed God in a rudimentary manner, it universally condemned everyone who tried to live up to its standard, until the Son of God came. He not only fulfilled the law completely, he lifted the standard of holiness even higher, demonstrating in His life what true son-ship looks like (see Matthew 5:17-48).
The placing of sons
Having considered the Son of God in His unique perfection, believers will naturally feel wholly inadequate to receive the honour of being called sons of God. Nevertheless, God has accomplished this at conversion through His astonishing and undeserved grace; we stand alongside the perfect Son within the family of God (Romans 8:29; Hebrews 2:11, 12).
The degree of honour associated with this individual son-ship is unparalleled in all of salvation history before Christ came.
While there are examples of individuals (rulers) and nations (Israel) being described as sons of God, only through Christ and since Christ has it been made possible for individuals to become sons of God in the fullest sense (Galatians 3:26). This is for several reasons, but fundamentally on account of His voluntary sacrifice on the cross, which has made eternal provision for sin and made it possible for sinners to be forgiven, declared righteous, and set apart for son-ship. The death and resurrection of the Son makes it possible for us to become sons.
Furthermore, as the Son of God, Jesus Christ also supplies the pattern and power to make our son-ship a reality. Israel was given a basic knowledge through the law; in Christ we have a full understanding of what it means to be a son of God (Hebrews 1:1). By focusing on Him, we are able to appreciate what it means to be a son of God practically; in life and character.