I will answer thee, and shew thee great and mighty things which thou knowest not.
There are different translations of these words. One version renders it, "I will shew thee great and fortified things." Another, "Great and reserved things." Now, there are reserved and special things in Christian experience: all the developments of spiritual life are not alike easy of attainment. There are the common frames and feelings of repentance, and faith, and joy, and hope, which are enjoyed by the entire family; but there is an upper realm of rapture, of communion, and conscious union with Christ, which is far from being the common dwelling-place of believers.
We have not all the high privilege of John, to lean upon Jesus' bosom; nor of Paul, to be caught up into the third heaven. There are heights in experimental knowledge of the things of God which the eagle's eye of acumen and philosophic thought hath never seen: God alone can bear us there; but the chariot in which He takes us up, and the fiery steeds with which that chariot is dragged, are prevailing prayers. Prevailing prayer is victorious over the God of mercy, "By his strength he had power with God: yea, he had power over the angel, and prevailed: he wept, and made supplication unto Him: he found Him in Beth-el, and there He spake with us."
Prevailing prayer takes the Christian to Carmel, and enables him to cover heaven with clouds of blessing, and earth with floods of mercy. Prevailing prayer bears the Christian aloft to Pisgah, and shows him the inheritance reserved; it elevates us to Tabor and transfigures us, till in the likeness of his Lord, as He is, so are we also in this world. If you would reach to something higher than ordinary grovelling experience, look to the Rock that is higher than you, and gaze with the eye of faith through the window of importunate prayer. When you open the window on your side, it will not be bolted on the other.