Once upon a time, Paul told the new believers in Thessalonica: “So, for this reason we give thanks to God without fail: because when you received the proclaimed word from us, that is, the word of God, you received it, not as a human message, but as what it really is, the word of God” (1 Thess 2:13).
With these words, Paul communicates that behind the apostles’ success was that they prayed. And in fact, later on he asks them, “pray for us, brothers and sisters, that the word of the Lord might run well and be glorified by its hearers, just as it was with you” (2 Thess 3:1). The successful sharing of the word is prayerful. Paul did not write books on “Proven Methods for Successful Evangelism.” Pastors did not travel to Corinth and lay down bags of denarii to see his PowerPoints on “The Seven Irrefutable Principles of Preaching.” Although it can be proven that he used methods, the heart of the matter for Paul is that neither strategy nor methodology can bring down the power of God from heaven.
I was shocked by the outcome of a little experiment: I selected from my shelf four very informative homiletics texts, which I had to read in college and seminary. One is a classic from the late 19th century; the others are more recent. I scanned through them to see what the writers had to say about prayer and its role in preaching. First, the older book emphasized the importance of how to organize one’s thoughts and of how to develop sound biblical exegesis. It offered no instruction about prayer. I laid it aside, assuming that it was an aberration. But the second book told the same story. Likewise the third and the fourth. I’m tempted to name names, but will not so that I may concentrate on this one point: all four of these authors waxed eloquent about how only God’s Word has the power to change people’s lives. Not one connected that truth with the need for prayer, neither in the exegesis or delivery of a message or its follow-up. I imagine that all of these writers would rail against the creeping secularization of Western civilization. Yet in effect they have offered secularized guides to preaching and evangelism by not urging preachers to their knees.
Missionary texts too regularly fall into the same mistake; likewise those texts which tell how to counsel, teach, cast a vision. And, sorry, neither can I accept that these authors simply took it for granted that we will all be praying, and hard. When a Christian leader goes off track, prayer is the first thing that goes missing.
It is not enough to communicate the Bible or to teach it based on solid exegesis. Its message will remain mere words if the Spirit does not act to change people’s lives. And the further a Christian strays from the apostolic model, the less likely it will be that the Word will have an impact.
Additional thought: Once again, some will say, well, these textbooks took for granted that the preacher is a person of prayer. Once again I reply, that that is precisely the point that cannot be taken for granted. The majority of North American pastors report that they do not pray as they should, and so a guide to preaching must zero in on the theme of prayer. What foolish person would write a Complete Guide to Driving and fail to mention, “By the way, do not drink and drive”? What firearms course would leave out, “Oh and, always assume a gun is loaded, and never point it at anything you don’t want to shoot”? The excuse “well, everyone surely knows about prayer” is beyond lame, it is culpable negligence. 
 Both of these expanded translations are from my upcoming commentary on 1-2 Thessalonians in the Zondervan Exegetical Commentary on the New Testament.
 These two verses and others have startling implications for one’s doctrine of election: if we pray for people to receive the gospel, are we not implying that God could intervene in their hearts and “call” them to faith, even if they are not disposed to believe? See especially J. I. Packer, Evangelism and the Sovereignty of God (Downers Grove, IL: IVP, 2009; orig. 1961), chapter 1.
 It will be obvious to his fans that I am not thinking of Charles Spurgeon’s Lectures to My Students. Spurgeon was adamant about the need of “The Preacher’s Private Prayer,” in Chapter III. He thereby proved once again that he was the heir to the Puritans.
 I am pleased to add (March 5, 2015) that I just ran into a fine article on prayer and preaching: see James E. Rosscup, “The Priority of Prayer in Preaching,” Master’s Seminary Journal 2.1 (1991): 19-44. He mentions positively the role of prayer in the two homiletic books by Andrew W. Blackwood: Preaching From the Bible and The Preparation of Sermons.
“Look before you leap; pray before you preach,” by Gary Steven Shogren, Seminario ESEPA, San José, Costa Rica