"Fear not, Abram: I am thy shield, and thy exceeding great reward." What a statement! Whatever the intended meaning was, clearly Abraham took it to mean that God was THE source... the ONLY source of supply that Abraham would ever need.
It becomes immediately obvious what was important to Abraham; what he wanted God to give him. He wanted someone to carry on his name, his line and his land when he was gone. He wanted a son.
It can be reasonably postulated that men hunger naturally and inexplicably for immortality. Some men sense that they will find it in fame, others in infamy... and some (apparently) in procreation. Abraham is our current example of that. The problem: Abraham was too old to have a son (or so he thought), so he mused that maybe somehow God could bless one of his closest and most trusted servants (Eliezer) as if he were actually a son. God had other ideas.
In verse six we read one of the most succinct doctrinal statements in the Bible. This is the only way that any of us can be reckoned righteous before God... God must impute it to us. On the basis of belief - God decrees innocence! Why? Because God values faith! Never lose sight of that. He only grants justification, innocence, holiness, salvation and heaven to those who learn to trust Him in this life.
As God commonly does, He immediately gave Abraham a job to do. God told Abraham to offer a sacrifice of five animals; a heifer, a female goat, a ram, a turtledove and a pigeon. Abraham cleaved each of the three larger beasts into two sections (evidently something like a chef would butterfly a steak). Then he laid them out along with the two birds... and he waited.
That evening God put Abraham to sleep and made a one sided covenant with him. Why did God put Abraham to sleep? So he wouldn't mess anything up? Because he had nothing to contribute? Because God doesn't need our help in order for Him to do the things that He is doing? One thing is for sure; as God passed between those pieces (in the form of a smoking furnace and a burning lamp) He was obligating Himself to bring His promises to pass. Regardless of Abraham's future and regardless of the future of his children... ultimately, everything that would be necessary in producing the SEED of Abraham (which was also the SEED of Eve) was sure to come to pass. God said so!