Yitzhkak (Isaac) seems to have repeated a number of events from Abraham’s life: a famine and claiming his wife was his sister. Yitzkhak also seems to have been obsessed with digging wells, but what should get our attention are messianic symbols of three days of live and death in the ground.
Is the purpose of this story to tell us that Abraham was a coward lacking in faith that he would use his wife to protect him from death? No, God brought Abraham there to teach Abimelech a lesson.
This incident gave Abimelech a good dose of humility as well and that’s a lesson we would do well to learn. It’s more pleasant to learn from other people’s mistakes than our own.