In the opening pages of Union with Christ: Reframing Theology and Ministry for the Church,
J. Todd Billings calls attention to a particular image used in Scripture to
explain what Jesus, by his life, death and resurrection, has accomplished for
believers: adoption (Rom. 8:14–17, 23; 9:4; Gal. 4:4–7; Eph. 1:5; 2:2).
Adoption, in the ancient Roman world, usually involved adults being adopted in order that an heir might be arranged for a
household (p. 18); thus, adoption came with the privilege of an inheritance but
also with the responsibilities of living in a manner fitting of being an heir
and a member of the adoptive family. There is a particular intimacy and
nearness of God to his adopted children communicated by this familial language.
In fact, as Billings says, there is something about the nearness of God that is
unnerving. It blows apart our ability to think of God as a conveniently
available lifeguard—there and ready to help if needed but who can otherwise be
ignored while we have fun. Adoption confers on believers an identity as adopted
children that was not earned or acquired by our affability. No, as Galatians 4:4–6
informs us adoption presupposes a God-initiated encounter through the Spirit
whereby we are made children of God apart from any thing we've done or will do.