This article in Time magazine tells how the stories that we tell ourselves help determine our happiness.
While our ultimate goal in life is not to necessarily bring about "happiness," we can and should seek to help people discover the biblical shalom--goodness, peace, and meaningful life--which often leads to happiness. And changing people's self-understanding by helping them discover and adopt a new story is a way to bring about this happiness.
If this is true, then it is yet another reason why our sermons ought to seek to help people enter into the Christian story of redemption. Having stories as illustration is nice, but really, illustrating the purpose and meaning of a life with Christ should be the ultimate goal.
By taking this approach, God works through preaching to help people who are depressed about their current lives to see how a life with Christ can "redeem" their life's story and give them meaning and hope. And this, so say the therapists, may bring about greater happiness in this life--and certainly in the life to come.
Want an example? How about the apostle Paul and legalism? Before Paul encountered Christ, he was a legalistic,violent man, zealously persecuting Christians. After encountering Christ, he became the most passionate proclaimer of God's grace in all of the New Testament.
What are some other biblical and current day stories that could reshape people's self-understanding and give them hope and meaning?