Genesis 20:9

And Abimelech called Abraham and said to him, “What have you done to us? How have I offended you, that you have brought on me and on my kingdom a great sin? You have done deeds to me that ought not to be done.” (Genesis 20:9 NKJV)

Was Abimelech following The Lord? Yes! But was He the chosen people? No. Is embarrassing when we compromise and get called out by people who don't even claim to be for The Lord. God can use anything to get our attention. How much better is a soft small voice than a rebuke from someone who isn't even Christian?