Justification is a forensic idea, conceived in terms of law, and viewing
God as judge. In justification, God declares of penitent believers that
they are not, and never will be, liable to the death that their sins deserve,
because Jesus Christ, their substitute and sacrifice, tasted death in their
place on the cross.
But contrast this, now, with adoption. Adoption is a family idea,
conceived in terms of love, and viewing God as father. In adoption, God
takes us into his family and fellowship, and establishes us as his children
and heirs. Closeness, affection and generosity are at the heart of the
relationship. To be right with God the judge is a great thing, but to be
loved and cared for by God is a greater
J.I.Packer