God chose the Israelites to be his people, his nation, his children. And so they are his children, a family established through the covenant God ratified with Abraham. At the heart of the covenant was the understanding that Israel “would acknowledge that the Lord is God” and that they would “keep his statutes and his commandments, which I am commanding you today for your own well-being and that of your descendants after you.”
The descendants of Abraham who had heard God’s call of election and embraced it were God’s chosen people. Yet the world was full of other people, also created by God, also beloved by God. From the beginning of the covenantal relationship, Abraham was told “no one but your very own issue shall be your heir” (Gen 15:4). But there was an additional promise: “In you all the families of the earth shall be blessed” (Gen 12:3). How would God be revealed to the other families of the earth? How would the other families of the earth enter the covenant and become heirs to the promises of God?
The language of families here is significant, for it is through the revelation of God as Trinity, the divine family, that all other families of the earth would be invited into the covenant family. For the reality of the Trinity did not emerge for the earliest Christians in the context of complex philosophical discussions but in the experience of God as Father, Son and Holy Spirit. As Pope Benedict XVI stated in 2006, “The intimacy of God himself, discovering that he is not infinite solitude but communion of light and love, life given and received in an eternal dialogue between the Father and the Son in the Holy Spirit— lover, beloved and love,” revealed the relational nature of God through the guidance of the Holy Spirit and by the incarnation of Jesus Christ.
And it was by means of the revelation of God as Father, Son and Holy Spirit that the early Christians came to know themselves as children of God, adopted into the family and covenant of God. The Spirit, Paul tells us, empowers us to understand that we too are children of God, for through the Spirit we are able to cry “Abba! Father!” This Spirit-infused call to God as Abba is an explicit recognition of our lineage: we belong in this family, for “it is that very Spirit bearing witness with our spirit that we are children of God.”
But the pathway to entering the family as heirs—children destined to share in the gifts and promises of the Father in the kingdom of God—was blazed for us by the obedience of the Son. As Paul says in Gal 3:39, “If you belong to Christ, then you are Abraham’s offspring, heirs according to the promise.” Christ, through his suffering and death for us, has made us “joint heirs with Christ,” worthy of adoption into God’s family. The Greek for “heir,” klêronomos, is combined with the Greek for “with” to make synklêronomos, “joint heirs.” We belong to the family of God because we belong to the Son, who has made us “joint heirs.” Through the true “heir” we are simply joined with our covenantal and divine family.
We are welcomed into God’s family as joint heirs because of the love of the Trinity for us. The Trinity models the nature of the family by allowing us to experience the source of all love. It is because of the Trinitarian model of love for us and our experience of that love that Jesus instructs us to go out and make the family bigger. We belong in the family of God, but so do those who have not yet come home.
When Jesus instructs the apostles to go out, “baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything that I have commanded you,” it is only an expansion of the covenant call to Abraham and the people of Israel to “acknowledge that the Lord is God” and to “keep his statutes and his commandments.” True, we have learned something new about the nature of God and the extent of God’s family, but the call is the same: Come home and be loved.