This is just about the best book I've read on the subject of changing the way you think and act. It's certainly the number 1 book I'd recommend to people wanting something on that sort of topic.
Tim Chester starts from a well-thought-through theology of who people are and why we sin. He avoids the usual pitfalls of legalism and saying that sin doesn't really matter. He really questions and challenges our motivation to change in a really helpful way. Brilliant.
Here are some quotes:
For all eternity your past experience of evil will enhance your eternal experience of glory.
Listen to Ed Welch: 'Perhaps the person is mad at himself for repeating the same sin over and over again. This is actually a veiled form of pride that assumes he is capable of doing good in his own power. He is minimising his spiritual inability apart from God's grace.' Jerry Bridges claims: 'God wants us to walk in obedience - not victory... We are more concerned about our own victory over sin than we are about the fact that our sins grieve the heart of God.'