How do we know that Abraham's faith was genuine?

The genuineness of Abraham's faith is evidenced in Genesis 15:6, where it states that Abraham believed God, and it was counted to him for righteousness. His faith was not mere intellectual assent; it was a deep trust in God that manifested in his obedience and life choices. Even when faced with challenges, such as the doubts surrounding God's promises regarding his offspring, Abraham's belief remained steadfast. His life exemplified faith in action, proving his genuine commitment to God's covenant and grace, as seen through his interactions and the choices he made throughout his life.