We believe the gospel has the power to changes lives – not just external behavior, but true, inner heart transformation. All other non-gospel belief systems try to change people’s behavior by motivating them through fear or pride.
A great example of this kind of non-gospel motivation is from the pilot episode of "The Cosby Show". Theo has just brought home another poor report card and Dr. Huxtable, played by the inimitable Bill Cosby, is upset and sits down with Theo to set him straight. What ensues is a humorous exchange with Monopoly money in which Dr. Huxtable essentially appeals to Theo’s greed and his desire to get a girlfriend. In other words – study hard in school because that way you can make a lot of money and get cute girls. (See video for clip from show.)
What’s wrong with this approach? You’re basically using socially acceptable sins (greed and pride) to battle socially unacceptable sins (laziness) – a tactic perfected by Asian parents. It might prove successful at changing the outward behavior, but the underlying heart condition (living selfishly) remains untouched. This is essentially the problem Jesus had with the Pharisees. On the outside, they looked upright and moral, but their underlying heart motivations were sinful – they only obeyed the law in order to impress people and to put God in their debt. In Jesus’ penetrating critique, he calls them “whitewashed tombs, which outwardly appear beautiful, but within are full of dead people’s bones and all uncleanness” (Matthew 23:27).
So what is the solution? How can messed up people truly experience heart transformation? The answer is the gospel. The gospel is the one truth that when we believe it, to the extent that we believe, will create a new heart and new motivations. Because of the gospel we are no longer ruled by fear (because in Christ our sins are forgiven) nor by pride (because we are secure in our identity in Christ), but rather we are compelled by love and gratitude. In other words, the gospel means that we no longer obey in order to be loved by God, but because we are already loved, we want to obey. To learn more, read Idols of the Heart by David Powlison.