Hughes Oliphant Old:
For many generations American Protestants have prized spontaneity in public prayer. I hope it will always be so. One has to admit, however, that the spontaneous prayer one often hears in public worship is an embarrassment to the tradition. It all too often lacks content. It may be sincere but sometimes it is not profound. One notices sometimes that the approach to prayer that these prayers reveal is immature, if not simply misleading. Spontaneity needs to be balanced by careful preparation and forethought. It needs to be supported by an intense prayer life on the part of the minister. One must be well experienced in prayer to lead in prayer. One can hardly lead if one does not know the way oneself. Spontaneity has to arise from a profound experience of prayer.
Every kind of work, profession, every craft has its own terminology and its own technical expressions, and so it is with prayer. Those who would learn the techniques of prayer must master this technology.
—Leading in Prayer: A Workbook for Ministers (p. 5 and 7). While the author’s name sounds stuffy and regal, it isn’t reflected in his writing. Lucid, engaging and immensely helpful book on the topic, Leading in Prayer is probably the best single resource on the topic.
D.A. Carson also writes about the benefits of written prayers, notably the pedagogical (i.e. teaching) implications:
If you are in any form of spiritual leadership, work at your public prayers. It does not matter whether the form of spiritual leadership you exercise is the teaching of a Sunday school class, pastoral ministry, small-group evangelism, or anything else: if at any point you pray in public as a leader, then work at your public prayers.
Some people think this advice distinctly corrupt. It smells too much of public relations, of concern for public image. After all, whether we are praying in private or in public, we are praying to God: Surely he is the one we should be thinking about, no one else.
This objection misses the point. Certainly if we must choose between trying to please God in prayer, and trying to please our fellow creatures, we must unhesitatingly opt for the former. But that is not the issue. It is not a question of pleasing our human hearers, but of instructing them and edifying them.
In brief, public praying is a pedagogical [teaching] opportunity. It provides the one who is praying with an opportunity to instruct or encourage or edify all who hear the prayer. In liturgical churches, many of the prayers are well-crafted, but to some ears they lack spontaneity. In nonliturgical churches, many of the prayers are so predictable that they are scarcely any more spontaneous than written prayers, and most of them are not nearly as well-crafted. The answer to both situations is to provide more prayers that are carefully and freshly prepared. That does not necessarily mean writing them out verbatim (though that can be a good thing to do). At the least, it means thinking through in advance and in some detail just where the prayer is going, preparing, perhaps, some notes, and memorizing them.
Many facets of Christian discipleship, not least prayer, are rather more effectively passed on by modeling than by formal teaching. Good praying is more easily caught than taught. If it is right to say that we should choose models from whom we can learn, then the obverse truth is that we ourselves become responsible to become models for others. So whether you are leading a service or family prayers, whether you are praying in a small-group Bible study or at a convention, work at your public prayers.