Then Abimelech called Abraham and said to him, “What have you done to us? And how have I sinned against you, that you have brought on me and my kingdom a great sin? You have done to me things that ought not to be done.” And Abimelech said to Abraham, “What did you see, that you did this thing?” Abraham said, “I did it because I thought, ‘There is no fear of God at all in this place, and they will kill me because of my wife.’ Besides, she is indeed my sister, the daughter of my father though not the daughter of my mother, and she became my wife. And when God caused me to wander from my father’s house, I said to her, ‘This is the kindness you must do me: at every place to which we come, say of me, “He is my brother.”’” Genesis 20:9-13.
This seemingly odd story has something to say to us other than, “don’t try passing your wife off as your sister.” It could be, “don’t be so afraid of godless people that you don’t tell them the truth.”
It seems unbelievable that Abraham would be so afraid for his life in light of the fact that God has promised them a child. I believe this is the reason God intervened directly, appearing to Abimelech in a dream, to stop this foolishness immediately. There may have been no fear of God in this place before this event. But you can be sure there was after it.