The problem of lax and hypocritical Christianity is not a new one, and one of the best treatments of the entire subject is a classic [Holiness] written by J.C. Ryle (1816–1900), who served as the Anglican Bishop of Liverpool for twenty years…
Ryle’s work is convicting because he does not appeal to silly gimmicks and other manmade answers to the problem of sin. He appeals over and over to Scripture, to the Word of the living God, and he drives the Word of God home through careful and direct application. If you are complacent in your sin and do not want to be disturbed in your enjoyment of it, do not read Ryle [Holiness].
(Keith Mathison, A Christian Classic on Sanctification, Ligonier Ministries)
I also recommend The Pursuit of Holiness by Jerry Bridges and The Holiness of God by R.C. Sproul. – Samuel