Never Gonna Give You Up (слэш)

Sam has always believed in angels and nothing anyone has said has ever convinced him otherwise. Dean has always wondered how his brother could be so sure, to speak as though he knew beyond a doubt that there are good forces in the world, that angels do exist especially with all the crap that they’ve dealt with on a daily basis. Maybe it has something to do with the fact that Sam has a guardian angel he never told anyone about?