“So then those who are of faith are blessed with believing Abraham”
Paul draws the inference from his preceding argument that those who place their faith in Christ receive justification just as Abraham did.
those who are of faith
A person must appropriate salvation by faith. The emphasis is upon belief in this verse in contrast to who tries to keep the law like the legalists. The phrase “of faith” means faith is the source of their relationship with God.
are blessed with believing Abraham
God blesses those who trust in His promises. God always blesses those who respond to His grace.
There is a definite article [the] before “believing Abraham” in the Greek. We can best translate the phrase “believing Abraham” as “Abraham, the believer.” Belief was the essential character of Abraham. Abraham chose faith rather than works as his method for receiving God’s blessing.
God always roots our blessedness in grace.
God always blesses us, and those of all time, by faith. God wholly roots our blessedness in grace. It is a joy to know that we do not have to measure up to be acceptable to God. Jesus did all of the measuring up needed. God always blesses those who operate by faith.