120) Imitate Rahab? Seriously? - James 2:20-24

Do you ever wonder why God picks some of the people he picks to hold up as examples in the Bible? Some of the models we're told to emulate are people who have an awful lot of failure. We read about their lives, and you read ten terrible things they did for every one good thing they finally do.
There are other people in the Bible with no recorded failures. So why does God seem to pick such sketchy people for us to look to as examples to imitate?