Preaching assurance vs. preaching doubt

I have noticed that there are two kinds of preachers, especially when addressing young people: One kind tries to assure the listeners of their salvation in Christ, underscoring His grace and mercy and His atoning work on the Cross. The other kind tries to make the listeners question whether they are “really” Christians. (“Did you REALLY give your life to the Lord? Do you show the fruit of true faith? Does your life show evidence of true conversion? Maybe you need to commit your life to him again, just to be sure.”)

Granted the problem of nominal Christianity. And granted the need to make people realize how sinful they are so as to help them grasp their need of the Gospel. But I would argue that the latter approach can do great harm. The one thing that DOES make a Christian is faith in Christ. Doubt is the opposite of faith. To make a person doubt his or her salvation is, ironically, to destroy faith, rather than to build it up. Furthermore, these “are you really a Christian” messages have the effect of making the hearers look within, at their good works or their feelings or their piety or whatever. Surely, whenever we look honestly at ourselves we will find nothing to commend ourselves before God. Rather, what needs to happen is to encourage troubled or doubting souls to look OUTSIDE themselves to the Cross of Jesus and the promises of God’s Word, to objective facts about God’s disposition towards them (“Did God cause you to be baptized? Have you taken the Lord’s Supper and heard the words “given for you”?)

I wonder if the attempts to scare young people into greater piety may be having the opposite effect.