Galatians 3:6-7, 29

Just as Abraham BELIEVED GOD, AND IT WAS CREDITED TO HIM AS RIGHTEOUSNESS, [as conformity to God’s will and purpose—so it is with you also]. [Gen 15:6] So understand that it is the people who live by faith [with confidence in the power and goodness of God] who are [the true] sons of Abraham.

And if you belong to Christ [if you are in Him], then you are Abraham’s descendants, and [spiritual] heirs according to [God’s] promise.