(a) In Paul's teaching, he said that since no man could claim perfection, he could not be justified by acts of the law, but only by faith in Jesus Christ. Abraham was righteous not by the law, but by act of his faith in God's promise. Those who believe in salvation through obedience to the law have no claim to faith. Those who believe in God's promise through faith as Abraham did are heirs of God's kingdom. Law brings punishment because it leads to the knowledge of sin and transgression. Faith is based on grace, love and peace. Though Abraham was 100 years and his wife Sarah 90, yet they had faith in God's promise of a child. And God gave unto them Isaac

(b) The role of faith in the life of Christians today include:
(i) Faith assures Christians of eternal salvation.
(ii) It shows that Christians are no longer under the bond of law but under the grace.
(iii) It is by faith that Christians face the challenges of life with enough courage and confidence.
(iv) Faith is a motivator of Christians for good works, e.g. education, medicine, evangelization, etc.