According to J. C. Ryle:
A right heart is a heart that feels CONFLICT within it (Gal. 5:17). It finds within itself two opposing principles contending for the mastery – the flesh lusting against the spirit, and the spirit against the flesh. It knows by experience what Paul means when he says, “I see a law in my members warring against the law of my mind” (Rom. 7:23). The wrong heart knows nothing of this strife. The strong man armed keeps the wrong heart as their palace, and their goods are at peace (Luke 11:21). But when the rightful King takes possession of the heart, a struggle begins which never ends until death. The right heart may be known by its warfare, quite as much as by its peace.