Final answer:
Abram fails to show faith in God when he takes matters into his own hands to produce a son by agreeing to have a child with his wife's servant, Hagar.
Step-by-step explanation:
In the biblical account, Abram fails to show faith in God when he takes matters into his own hands to produce a son. Despite God's promise to make him the father of many nations, Abram and his wife Sarai are unable to have children. Sarai suggests that Abram have a child with their servant Hagar, and Abram agrees. However, this decision is a lack of trust in God's timing and plan, as God had already promised to provide them with a child.