God and Abram came to an agreement; God would make Abram's name great, and allow him many descendants. As a sign for this covenant, God changed Abram's name to Abraham.
“Leave this land with your family and descendants, and go to Canaan. I will help you birth a nation, and give your descendants a long and fulfilling life. These are my only conditions."
Abraham now circumsised himself and everyone in his family, as part of the conditions of their covenant.
God then instructed Abraham to travel from his father's home in Ur Kasdim to Canaan, so that he could raise a nation. (This nation would later be named Israel.)
One day while they were traveling, God spoke to him, and asked Abraham to count the dust on the ground. God promised his bloodline to have as many people as the dust particles of the Earth.
After living in Canaan for some time, God fulfilled one of his promises - he allowed Abraham and Sarah to finally have a child. They named him Isaac, and he would become one of the three patriarchs of the Israelites.
After Abraham and Sarah passed away, their bloodline continued, with the city of Israel (Previously Canaan) becoming one of the largest cities. Circumcision continued as a tradition, and also a sign of the Conditional Covenant to God.