"The promise in mind must still be Genesis 15:5 that Abraham's posterity would be as numerous as the stars. It was a promise without any conditions or requirements attached to it. God's Word came to Abraham as a gratitutious promise - not as law. He simply believed God and was justified".
John R W Stott - "BST Series - The Message of Romans" - IVP, Leicester (1994) - (p130).