Thomas Watson's The Doctrine of Repentance is a must read for those who earnestly desire to know the repentance God requires. Many books have been written on this topic, few have surpassed his work.

What's Different About This Version?
Phrases and words with little or no modern meaning, such as, "See how sin pleads custom, and that is a leopard's spot" have been changed to read, "See how we become accustomed to sin, just as a leopard does to his spots." In other words, it's easier to read!