There’s a lot of teaching in the New Testament about how Christians become adopted children of God (e.g. Rom 8:15, Eph 1:5). Adoption in Roman society at the time of the New Testament was different to adoption these days. It served a social function, in a similar way to an arranged marriage. ‘Suitable’ children were adopted into another family, which resulted in advancement for both the child and their birth family. And it’s the same with us and God. God has offered to adopt us as his children, so that we can benefit from his parenthood and receive an inheritance.
In the New Testament times, it was common practice for young boys to be adopted into another family to fulfil their need for a son in line with inheritance laws at the time. Far from being the child who could not be cared for by the family who put them up for adoption, in Roman times, the adopted child was often the oldest, with proven health and abilities. Adoption didn’t have any of the negative connotations that may be associated with it today. And the adopted child usually retained strong ties both with their birth and adopted family.
God has promised to adopt us as his children if we believe in him. In Romans 8, Paul explains to the church in Rome that believers have received the ‘spirit of adoption as sons [and daughters]’ and have the privilege to address God as ‘Abba Father’ (Rom 8:15). ‘Abba Father’ is a familiar term, somewhat equivalent to a young child addressing their father as ‘daddy’. As in Roman times, this adoption comes with a responsibility to our new family, but also an inheritance. In Ephesian 5, Paul reminds that church in Ephesus that they were predestined to be adopted sons and daughters of God (Eph 1:5) and to have an inheritance from God (Eph 1:11,14).
So where does this adoption as a child of God leave our relationship with our birth family? Sometimes there will be division when a new child is adopted by God – and a Christian may even have to choose between God and their birth family (Luke 14:26). However, remember that one of the 10 commandments is to ‘honour father and mother’, and this does not change when you become an adopted child of God (Eph 6:2). The ideal situation is that, just like in the Roman world, both the child and the birth family benefit from the adoption.
It is a comforting and humbling thought that all members of a church are children of God. Jesus too, whilst of course is highly exalted (Phil 2:9), is also described as being a child of God and therefore, our brother (Rom 8:29). So, a church is a family with God as the father and Jesus as our brother. Like all families, we will fall out from time to time, but should have a deep love for one another that grows from a shared sense of purpose and parenthood.