Charles H. Spurgeon on Psalms 18:6

The prayer of a single saint is sometimes followed with wonderful effects; "In my distress I called upon the Lord, and cried unto my God: he heard my voice out of his temple, and my cry came before him, even into his ears. Then the earth shook and trembled; the foundations also of the hills moved and were shaken, because he was wroth:" what then can a thundering legion of such praying souls do? It was said of Luther, iste vir potuit cum Deo quicquid voluit, That man could have of God what he would; his enemies felt the weight of his prayers; and the church of God reaped the benefits thereof. The Queen of Scots professed she was more afraid of the prayers of Mr. Knox, than of an army of ten thousand men. These were mighty wrestlers with God, howsoever contemned and vilified among their enemies. There will a time come when God will hear the prayers of his people who are continually crying in his ears, "How long, Lord, how long?" —John Flavel.