How astonishing it is that God wills to do His work through people. It is doubly astonishing that He ordains to fulfill His plans by being asked to do so by us. (…) I was amazed once to hear a seminary graduate say how adequate he felt for the ministry after his years of schooling. This was supposed to be a compliment to the school. The reason this amazed me is that the greatest theologian and missionary and pastor who ever lived cried out, “Who is sufficient for these things?” (2 Cor. 2:16). Not because he was a bungler but because the awful calling of emitting the fragrance of eternal life for some and eternal death for others was a weight he could scarcely bear. A pastor who feels competent in himself to produce eternal fruit–which is the only kind that matters–knows neither God nor himself. A pastor who does not know the rhythm of desperation and deliverance must have his sights only on what man can achieve.
Apart from prayer, all our scurrying about, all our talking, all our study amounts to “nothing.” For most of us the voice of self-reliance is ten times louder than the bell that tolls for the hours of prayer. (…) Both our flesh and our culture scream against spending an hour on our knees beside a desk piled with papers. It is un-American to be so impractical as to devote oneself to prayer and meditation two hours a day. And sometimes I fear that our seminaries conform to this deadly pragmatism that stresses management and maneuvering as ways to get things done with a token mention of prayer and reliance on the Holy Spirit. Refuse to believe that the daily hours Luther and Wesley and Brainerd and Judson spent in prayer are idealistic dreams of another era.
-John Piper, Brothers, We Are Not Professionals