God calls Abraham his prophet. Abraham knows God has promised him a nation of descendants, yet he still doesn’t trust him. Abraham pushed the boundaries of truth to help save himself from getting killed by King Abimelech. He and Sarah are indeed half siblings through their father; however, they were also married. Even though this seems repulsive to us, it’s in scripture. The Bible is not boring! So, even though Sarah was probably already pregnant with Isaac, King Abimelech took her away from Abraham. God visited him in a dream and told him he was a dead man for taking her. Of course, Abimelech returned her before doing anything lewd with her. God had so much love for Abraham and Sarah that he stopped this man in his tracks and forced him to make restitution for his crime by giving them sheep, oxen, servants, and silver. Abraham blessed him a prayed for him, his wife, and their people.
We know that we know that Jesus has saved us from the consequences of our sins, yet we still don’t trust him and continue to sin. If you have to lie, you don’t trust God to work out the details of a situation. That’s all there is to it. Yes, it’s difficult, but we need to learn to trust God from the lesson learned by Abraham.
Abimelech said unto Abraham, What sawest thou, that thou hast done this thing? And Abraham said, Because I thought, Surely the fear of God is not in this place; and they will slay me for my wife's sake. And yet indeed she is my sister; she is the daughter of my father, but not the daughter of my mother; and she became my wife. Genesis 20:10-12