Threats of Judgement: an evangelising tool?

Both in real life and in blogdom, the issue has come up of whether or not threatening unbelievers or heretics with God's judgement is a way of focussing the mind. Some seem to argue that God's judgement is real and therefore should be cited. Others argue that threats of judgement will get the attention of people and possibly convert them where proclamations of God's grace might not.

On that subject, there is an interesting statement mad by Fred Craddock in his Commentary on Luke regarding verse 54 of this Sunday's Gospel reading, Luke 9:51-62.

Craddock writes:

Jesus' disciples remember quite well scriptural precedent for calling down heaven's fire (II Kings 1:9-10), but they have forgotten the recent words of Jesus: when on a mission, acccept the hospitality offered you. If none is extended, shake the dust off your feet and move on (9:1-6). Is it not interesting how the mind can grasp and hold those Scriptures which seem to bless our worst behavior and yet cannot retain past the sanctuary door those texts which summon to love, forgiveness, and mercy? Jesus rebukes James and John for an attitude of revenge and retribution, an attitude totally foreign to his ministry and theirs.

If the apostles were called to leave judgement to the Lord, then I believe we are too.