Previously in Romans
Paul showed that all are without excuse, and need salvation from God's wrath (1:16-3:20). God demonstrated his favor and righteousness by rescuing believers through the atoning sacrifice of Jesus, freely acquitting them from sin (3:21-31).
Paul wrote that this acquittal from sin, justification, comes by faith and not by works of the law (3:28).
Romans 4 Outline
4:1-8
Justification by faith illustrated
4:1-5
Abraham counted as righteous
4:6-8
David rejoiced in God's forgiveness
4:9-12
Abraham esteemed righteous before circumcision
4:13-17
God's promise to Abraham
4:13-15
Promise came through faith, not law
4:16-17
Guaranteed to all Abraham's offspring, including faithful Gentiles
4:18-21
Abraham's unshakable hope and faith
4:22-25
Faith credited to Abraham as righteousness
Abraham's Example
Abraham's life was recorded in Genesis 11:27 to 25:11. God sent Abram from his family in Ur to the promised land of Canaan (Genesis 12:1-6). God made him a father of nations, and gave him the name Abraham which means "father of a multitude" (Genesis 17:1-8).
Abraham fully trusted God. He believed what God said and acted on his convictions. Believing God's promise to make him a great nation, Abram moved to a foreign country (Genesis 12:1-5).
When God told Abram his offspring would be numberless like the stars, he believed God, and it was counted to him as righteousness (Genesis 15:5-6).
Abraham's willingness to sacrifice Isaac at God's command demonstrated faith and obedience (Genesis 22).
Circumcision
The rite of circumcision was instituted by God to signify a covenant relationship between God and Abraham (Genesis 17:10-27). Jews practiced circumcision in New Testament times. Christians were not directed to be circumcised (Acts 15:5-11). God desired circumcision of the heart, trust in him and obedience to his will (Jeremiah 9:25-26, Romans 2:29).