I was reading a book on preaching and found this thought…something to chew on!
The Holy Spirit simply will not identify Himself with the unclean or unconsecrated. ‘Be ye clean, that bear the vessels of the Lord’ (Isa. 52:11). How completely God identifies Himself with the labors of His faithful spokesmen is shown in the ministry of Samuel. ‘The Lord was with him, and did let none of his words fall to the ground. And all Israel from Dan to Beersheba knew that Samuel was established to be a prophet of the Lord’ (1 Sam. 3:19–20). It must be remembered that the fruitfulness or sterility of a man’s ministry depends not nearly so much upon his native ability, his training, his skill, and his labor, as upon that which the Lord adds or withholds. ‘After preachers have preached ever so eloquently and long, when sinners are bowed, as great a wonder is wrought, and by God alone, as when Jericho fell.’ The walls of Jericho did not fall by the shouts of Israel, but by the breath of God.
-From How to Preach Without Notes by Charles W. Koller