Genesis 15
God promised Abram that his descendants would be as numerous as the stars in the sky (15:1-5)... Abram and his wife were both getting old and had no children. He questioned how God would keep His promise to make Abram into a great nation. God reassured him that his descendants would be as numerous as the stars.
Abram believed the LORD, and he credited it to him as righteousness (15:6).... This verse is among the most important. It shows us that despite always falling short of perfection, we can have righteousness credited to us because of our faith. Romans 3:21-24 explains this. Then Romans 4 expands on it.
Abraham illustrates that no one is saved by works (Romans 4:1-3).... Paul uses Abraham as an example to show that people aren't saved by works, but by faith.
Abraham illustrates that no one is saved by ritual (Romans 4:10).... Again, Paul uses Abraham to show that faith in Jesus is the only way to salvation. No ritual can save you. Even with baptism, if there is no faith, there is no salvation.
God will credit righteousness to the account of anyone who believes in Jesus (Romans 4:23-24)... Faith in Jesus is the only way to obtain righteousness and salvation.
God promised Abram the land of Canaan. Abram asked for assurance, so God made a covenant with Abram (15:8-18).... God knows the future and God has a plan. He tells Abraham what's going to happen in 400 years and that his descendants will face trials and suffering, but that God will rescue them. God planned to give specific land to Abraham and his descendants, but first He wanted to give the existing inhabitants a chance to repent of their sin, 400 years to turn from their ways. It shows that God has great patience in waiting for us to repent.
God is a covenant maker (Jeremiah 31:31, 33; Luke 22:20). Will you accept his covenant and believe?... God created a covenant with Noah and the sign for it was the rainbow. When God made a covenant with Abram, the sign was circumcision. With the covenant in the New Testament, the sign is the blood of Christ.