So we see that it is those who possess faith that are blessed with believing Abraham.

(Now the promises were given to Abraham and to his seed. God did not say 'and to seeds,' as if speaking of many, but 'and to your seed,' since He spoke of only one--and this is Christ.)

Why then was the Law given? It was imposed later on for the sake of defining sin, until the seed should come to whom God had made the promise; and its details were laid down by a mediator with the help of angels.

But we see that the child of the slave-girl was born in the common course of nature; but the child of the free woman in fulfilment of the promise.

See in what large letters I am writing to you with my own hand.