Consistency is one of the main things we look for in honorable people. Will they do what they say they will do? Do their behaviors resemble their values? One of the repeating themes in the stories of Genesis is that our protagonists are sadly quite inconsistent.
There is a tragic irony that on one page of the Bible a character can be noble and courageous, and then on the very next page they make a "heel-turn" and become faithless and vain. Despite the fact Abram and Sarai have been commended for their faith, in their impatience for a child to carry on their name they hatch an unholy plan that involves exploiting a vulnerable immigrant, sexual impropriety, cruelty, and irresponsibility (Genesis 16:1-16).
The bitter irony is that they know what it's like to be on the receiving end of those things! The Bible is never afraid to show the people of God their deep flaws, but the God of Abraham always holds the door open for redemption. Their stories are a warning for us to look for our own inconsistencies and repentantly turn to Christ for our own redemption.