Abram is presented to us as an old man without an offspring or heir. He is at the age of seventy-five when God comes to him with the offer of the covenant. Abraham stands for devotion, justice, compassion, faith, tact, and personal integrity. He is also seen as cunning, humorous, and pragmatic throughout the story. Abram is a man looking for his faith, and God asks Abram to leave his land and kinship to a land which God will show him. In exchange for Abram's faith and compliance, God will make of Abram a great nation, make his name great, bless those who bless him and curse those who curse him, and finally all the communities of the Earth will find blessing in him.
The covenant is a basic understanding between Abram and God that Abram and his people will assume that God is the one and only God. In exchange for their faith, God will initially provide them lands (Canaan) and riches. After Abraham is provided the lands and riches, he still needs a son or heir to carry on his name and provide descendants of his lineage. God comes through for Abraham, and provides him a child when he is 100 years old and Sarah is 99 years old. Although Abraham laughed when God told him that Sarah would give birth at her old age, Abraham had faith in God and believed that God would eventually provide Abraham with a worthy heir or successor in Isaac. Abraham continued to have faith in God whenever God spoke to Abraham, and as a final test of Abraham's faith, God asked Abraham to do the unthinkable.
God asked Abraham to sacrifice Isaac to the Lord in order to test Abraham's faith. God knew that if Abraham was willing to sacrifice his son, Abraham must truly believe in God. Abraham took Isaac away from their lands and traveled to where God asked him to set up an altar. Then, just as Abraham was about to sacrifice Isaac, a messenger of God's stopped Abraham. Abraham found out that this was God's final test before the covenant was finalized. God told Abraham that all his people must look to God as their god, and that all the boys must be circumcised on the eighth day after their birth. If Abraham would fulfill his part of the covenant, God would provide Abraham with the lands of Canaan.
Abraham must have faith in God throughout his journey because the God he speaks to asks him to leave his lands and kinsfolk to go to a promised land that Moses has never seen nor heard much about. God promises Abraham many things which were unbelievable or impossible without divine intervention, so Abraham's faith is always being tested. Abraham knows that his legacy will never continue without an heir, so his faith lets him continue and believe that he will still have a son even after he has aged so much. Another reason why Abraham must have faith is that the people following him have faith in Abraham. If at any time Abraham loses faith, he will not only risk breaking the covenant with God, but he will also be letting down all the people who had faith in him.