(a) God's promise to Abraham that his descendants would inherit the world was not because of his obedience to the law, but as a result of his faith in God. The knowledge of the law leads to punishment. Without the law, there would be no sin. The promise to Abraham's heirs depends on faith and the promise, however, is not only for Abraham's descendants alone, but for all who believe by faith just as Abraham the father of the faithfuls whose faith in God was fully illustrate when he believed God's promise that he would be the father of all nations. Despite the old age of both Abraham and Sarah, Abraham did not doubt God's promise, but held on to the faith he had in God. Because of one man's disobedience, many became sinners and were condemned due to Adam's sin. By the grace of God through the righteousness in Jesus, mankind has been saved. Law came to multiply transgression, where sin increased, grace abounded.

(b) The significance of law and grace in a Christians' life is that:
(i) If we obey the law, it would not lead to salvation. It is rather an end in itself but a means to an end.
(ii) It is the belief of the Christian that he had died to sin through his baptism a faith in Jesus.
(iii) Through God's grace, Christians would live eternally with Jesus in heaven.