Final answer:
The key characteristic of Abraham is his intense commitment to the worship of one God. His first great act of faith was agreeing to the Covenant and his immediate disobedience was having a child with his servant Hagar.
Step-by-step explanation:
The key characteristic of Abraham is his intense commitment to the worship of one God. His first great act of faith was agreeing to the Covenant, a promise made between God Yahweh and the Hebrews. In this Covenant, the Hebrews pledged their devotion and worship in return for a land of peace and prosperity. However, Abraham immediately disobeys by having a child with his servant Hagar instead of waiting for God's promise to be fulfilled through his wife Sarah.