A word from A.W. Pink on the preacher’s duty of prayer:
The preacher’s obligations are not fully discharged when he leaves the pulpit, for he needs to water the Seed which he has sown… [T]he apostles devoted themselves “continually to prayer, and to the ministry of the word,” and therein have they left an excellent example to be observed by all who follow them in the sacred vocation. Observe the order, and not only observe but heed and practice the same. The most laborious and carefully prepared sermon is likely to fall unctionless on the hearers unless it has been born out of travail of soul before God. Unless the sermon be the product of earnest prayer we must not expect it to awaken the spirit of prayer in those who hear it. As we have pointed out, Paul mingled supplications with his instructions. It is our privilege and duty to retire to the secret place after we leave the pulpit and beg God to write His Word on the hearts of those who have listened to us, to prevent the enemy from snatching away the Seed, to so bless our efforts that they may bear fruit to God’s eternal praise.
Luther was wont to say, “There are three things which go to the making of a successful preacher: supplication, meditation, and tribulation.” This was taken down by one of his students from his “Table Talks.” We know not what elaboration the great Reformer made, but we suppose he meant that prayer is necessary to bring the preacher into a suitable frame to handle divine things and endue him with power; that meditation on the Word is essential in order to supply him with material for his message; and that tribulation is required as ballast for his vessel, for the minister of the gospel needs trials to keep him humble, as the apostle was given a thorn in the flesh that he might not be unduly exalted by the abundance of the revelations given him. Prayer is the appointed medium of receiving spiritual communications for the instruction of our people. We must be much with God before we are fitted to go forth and speak in His name.
From A.W. Pink, Gleanings From Paul