It is what it is. This is what I tell others when they ask me how things are going, with me, with work, with life. It is what it is. Although I sometimes forget, there is a reason I say it. The phrase is packed with really good theology (I think.)
By saying "It is what it is" one reveals submission to the providence and sovereignty of God. I say "It is what it is" because I then immediately remind myself that God is ultimately in control and most of life's unpleasant circumstances are for training in righteousness and to teach perseverance.
Living through situations that require an "It is what it is" attitude are painful. Part of the growth process is coming to terms with the fact of the theology behind another statement that is packed full: When the pain of not changing becomes greater than the pain of change, then lasting change will occur.
It is what it is but I feel the need to make some changes.