Covenants.
It is called the "Covenant"-- the promise Abraham made with God, and God made with Abraham.
The bible has thousands of promises in the bible, some are to be fulfilled still.
The symbol of God's covenant with Abraham is circumcision, which was the physical sign of the covenant between God and Abraham's descendants. This practice was to be continued throughout generations as a reminder of God's promises to Abraham and his descendants.
Abraham began serving God long before God spoke to him. He didn't serve God because of Divine promises. However, the prophecies and promises certainly encouraged him.
his son
God called Abraham righteous because of his faith and obedience. Abraham trusted in God's promises, demonstrated by his willingness to leave his homeland and obey God's commands, such as when he was prepared to sacrifice his son Isaac. This faith and obedience showed Abraham's righteousness before God.
Abraham
Abraham was the first patriarch of gods family.
Abraham at the ripe old age would have a son, whom he named isaac.
Jesus Christ
The statement "The people first had a polytheistic religion that involved worshiping many gods" does not accurately describe the story of the ancient Hebrews. The ancient Hebrews were monotheistic, believing in one God. The statement "The promises that God made to Abraham" is a correct description of the story of the ancient Hebrews, as God made a covenant with Abraham promising him land and descendants.
Jesus Christ