The comparison drawn in verse 6 between the experience of Abraham and that of the Galatians requires the conclusion of verse 7: Understand, then, that those who believe are children of Abraham. The common family trait of faith is the decisive factor. Anyone characterized by that trait is definitely identified as a member of the family.

We might have expected the conclusion in verse 7 that God credits righteousness to all those who are of faith. That conclusion would have been more closely related to the previous verse's quotation of Genesis 15:6. But the fact that Paul's conclusion has to do with the identity of the children of Abraham shows that this was the major concern. The troublemakers insisted that circumcision was the indispensable sign of the covenant family. Paul uses Genesis 15:6 to prove that only those who believe can legitimately make the claim that they belong to the people of God as children of Abraham.

Faith is the true sign of covenant. In the context Paul clearly defines faith as faith in Jesus Christ (v. 16). So now identification with Christ by faith, rather than identification with the Jewish nation by circumcision and works of the law, provides the basis of belonging to God's covenant family.

The continuity between Israel, the "children of Abraham," and the church is clearly stated here: Christians have roots; they have a clear identity; they belong to the ancient people of God that began with Abraham.