Deep study
Genesis 12-25 - promise, covenant, and faith counted as righteousness
Abraham is called the father of all who believe (Romans 4:11). To understand him is to understand how God saves: by promise, received through faith.
Abram was born in Ur of the Chaldeans, a sophisticated city steeped in moon-worship, and later settled in Haran. Joshua 24:2 tells us plainly that his family served other gods. So when God said, Go from your country and your kindred (Genesis 12:1), the call cut Abram off from everything that anchored a man in the ancient world: land, clan, and gods. There was no merit in Abram that prompted the call. It was sheer grace that reached into a pagan household and set one man apart for a purpose that would touch all nations.
God's word to Abram in Genesis 12:1-3 is a sevenfold promise climaxing in a global blessing: in you all the families of the earth shall be blessed. In Genesis 15, when Abram asks how he can be sure, God formalizes it with a covenant. Animals are cut in half and, by custom, both parties would walk between the pieces, in effect saying, may this be done to me if I break my word.
But Abram does not walk. God alone, as a smoking fire pot and flaming torch, passes between the pieces. The meaning is staggering: God binds Himself, and Himself alone, to keep the covenant. The promise rests not on Abram's faithfulness but on God's.
Genesis 15:6 is one of the most important sentences in the Bible: he believed the LORD, and he counted it to him as righteousness. Abram had no temple, no law, no works to show. He simply trusted the promise, and God credited him with right standing.
Paul builds his whole doctrine of justification on this verse (Romans 4; Galatians 3). And he is careful to note the timing: Abraham was justified in Genesis 15, years before he was circumcised in Genesis 17. Righteousness came by faith alone, before any rite or work - so that he could be the father of all who believe, circumcised or not (Romans 4:9-12).
In Genesis 22 God tells Abraham to offer Isaac, the son of promise. Abraham obeys, trusting that God can even raise the dead (Hebrews 11:19). At the last moment God provides a ram caught in a thicket, and Abraham names the place The LORD will provide (YHWH-Yireh).
The scene is dense with foreshadowing: a beloved son, a wood-bearing journey to a hill in the region of Moriah - where the temple would later stand - and a substitute dying in the son's place. It is a living parable of the Father who would not spare His own Son (Romans 8:32) on that same range of hills.
Paul says the promises were spoken to Abraham and to his offspring, who is Christ (Galatians 3:16). The blessing to all nations comes through Jesus, Abraham's seed. And the way Abraham was justified, by faith apart from works, is the way everyone is justified still, so that those of faith are the sons of Abraham (Galatians 3:7).
Abraham himself was looking past Canaan. Hebrews says he was waiting for the city that has foundations, whose designer and builder is God (Hebrews 11:10,16) - the very city that descends at the end of the Bible, the new Jerusalem with twelve foundations (Revelation 21:14). And the promise of descendants beyond counting, like the stars, finds its answer in the great multitude that no one could number, from every nation, standing before the throne (Revelation 7:9). The faith that justified one wandering man becomes the song of a countless, worldwide family.