Hi Abraham belonged to a family that believed in God Almighty, so he was not a sole worshiper. The relationship started with his father Terah that left his hometown and travel to the land of Canaan, Genesis 11:27–32. They were members of the household of the patriarch Terah Abram, Sarai, Lot, and his family as they traveled to a foreign land possibly starting their lives as nomadic. When Terah died in the land of Harran where they had settled God spoke with Abram to continue on to a land that God would show him and thus built a relationship with Abram after Terah's death being 75 years old, Genesis 12:1–4. For 100 years God continued to interact with Abram changing his name and establishing his family roots through relationships with chosen sons of Abraham until the promise of inheriting what is now Israel was fulfilled, Genesis 25:1–11.