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 written by J.C. Ryle (1816–1900), who served as the Anglican Bishop of Liverpool for twenty years. Ryle was a deeply committed and non-compromising evangelical Christian. In fact, Charles Spurgeon referred to him as an “evangelical champion.” His book Holiness has been reprinted numerous times since its original publication in 1879. It is deservedly considered a Christian classic on the subject of sanctification. It ranks up there with the work of John Owen on the mortification of sin. Read more
Also see J.C. Ryle's Holiness: Its Nature, Hindrances, Difficulties, and Roots.