I strongly resist the notion that learning about homiletics means that your preaching will automatically become professional, fleshly and spiritually cold. Some do end up there. Some do become mechanistic in their approach. But I hold that it is right to be a good steward of the opportunity to develop as a preacher, as long as the process is saturated in prayer, as long as the personal relationship with the Lord doesn’t grow cold and become a thing of the past.
So when I teach a beginners intro to preaching, I always make it abundantly clear that the process I teach is not a machine into which a text is fed and a message emerges at the other end. The process is a logical approach to developing a message, but it should be pursued in dependence upon the Lord through conversational prayer throughout the process. Pray as you select a passage, pray as you study it, pray as you identify its purpose and pray as you clarify its main idea. Pray as you consider who will hear the message, pray as you determine the purpose of the message, etc.
Having said all that, there is still a difference between prayerful preparation and just plain prayer. Make sure that all your prayer is not running in parallel to preparation so that you fail to spend time with the Lord about the preaching opportunity. Take time away from your PC, your notes, etc., and make sure you spend time talking to Him about the message, the people, the opportunity, your own heart and motivation in preaching, etc.
Time taken out of preparation to spend in focused prayer before the Lord is not time wasted. Let’s be sure to prepare prayerfully. And let’s be sure to pray as part of preparation. Prayerful. And prayer. Both.