Paul David Tripp from “Instruments in the Redeemer’s Hands”

“If my heart is the source of my sin problem, then lasting change must always travel through the pathway of my heart. It is not enough to alter my behavior or to change my circumstances. Christ transforms people by radically changing their hearts. If the heart doesn’t change, the person’s words and behavior may change temporarily because of an external pressure or incentive. But when the pressure or incentive is removed, the change will disappear.”
Paul David Tripp
Instruments in the Redeemer’s Hands, p. 62.