There is an article on blogs4God, written by Jen Kibler-McCabe, titled scare tactics. It started by analysing the reason why Luther nailed 95 theses - the fact that the Catholic church at that time is selling the indulgences using scare tactics, i.e. if you don't buy, you'll burn in purgatory. Jen then moves to the main point - evangelicals today should not use scare tactics to preach the gospel. On one hand, God loved us by sending his son to die for the sinners (Romans 5:8). On the other hand, God still hates the sin that separates us from God, but will take us back if we repent. Here's the conclusion:
I'm exhorting all of you to be aware of how you are preaching the Gospel. Our actions witness just as much to the Gospel as our words and our actions are frequently what turn people away. So... in the words of St. Francis: Preach the Gospel and if you must, use words. Just not nasty ones.
I do agree that by condemning the sinners might not be the best way to evangelise to the non-Christians, neither is it effective challenging the already-saved. However, we must also realise the intersection between the tactics and truth here.
I wonder whether "using scare tactics" was really the reason why Martin Luther turned his head opposing the Catholic church, or is it actually his realisation of sola gratia - man is saved by God's gracious generosity alone, instead of the act of purchasing the ticket to avoid purgatory. Neither way, the danger is still there, we still need to understand the very consequence of God's judgement, and we still need to be saved from His wrath. Some people think that we should not preach the idea of hell in church, as though it is some kind of scare tactics. But then where were we saved from? And why does the author of Hebrews urged Christians to continue meeting together? "but encourage one another, and all the more as you see the Day drawing near" (Hebrews 10:25) - because of the very fact that we should not be those who shrink back and are destroyed (Hebrews 10:39)!
And we shall not forget the very act that Jesus did on the cross - as propitiation (hilastērion) for God's anger. It is more than just dealing with the penalty of eternal suffering in hell, but absorbing the very wrath of this personal God. God is angry at us, for the fact that we have rejected him as our creator and ruler. That is the same God who has his anger burning against the rebellious Israelites in the Old Testament by destroying the nation using the Babylonians, against the sinful Canaanites by commanding Joshua and the Israelites to wrap out the land, against the wicked nations by sending flood covering the earth. God hates sin, and He also hates the sinners, as our hearts are in fact already polluted with all kinds of wickedness in this world. We, as enemies of God, are totally valueless to him. We don't deserve a bit of goodness from him.
And it is because of the scare tactics, the mercy of God is even more gracious. It is necessary for us to realise what we have been saved from, for us to continue to stand firm in trusting him, and praise him for what he has done.