The story of Abimelech is really a story of a person being found out in his sins.  Life experience teaches us that we can't keep our sins hidden forever, and though we may get away with them in the short term, there will be consequences in the long term.  Abimelech thought he was sitting pretty in his position as leader of Israel, but his sins found him out, and he was forced to lose everything – including his life.  Do you have any secrets?  You can run, but your secrets will eventually be found out.  It's better to get them out in the open so they can be dealt with.  Thankfully God is gracious, and forgiveness is readily available when we seek it.