There is a remarkable passage in Paul's Roman letter about prayer and God's will (Rom_8:26-28). "And in like manner the Spirit also helpeth our infirmity: for we know not how to pray as we ought; but the Spirit Himself maketh intercession for us with groanings which cannot be uttered; and He that searcheth the hearts knoweth what is the mind of the Spirit, that He maketh intercession for the saints according to the will of God."
Please notice: these words connect back with the verses ending with verse seventeen. Verses eighteen to twenty-five are a parenthesis. As the Spirit within breathes out the "Father" cry of a child, which is the prayer-cry, so He helps us in praying. It is our infirmity that we do not know how to pray as we ought. There is willingness and eagerness too. No bother there. But a lack of knowledge. We don't know how. But the Spirit knows how. He is the Master-prayor. He knows God's will perfectly. He knows what best to be praying under all circumstances. And He is within you and me. He is there as a prayer-spirit. He prompts us to pray. He calls us away to the quiet room to our knees. He inclines to prayer wherever we are. He is thinking thoughts that find no response in us. They cannot be expressed in our lips for they are not in our thinking. He prays with an intensity quite beyond the possibility of language to express. And the heart-searcher—God listening above—knows fully what this praying Spirit is thinking within me, and wordlessly praying, for they are one. He recognizes His own purposes and plans being repeated in this man down on the earth by His own Spirit.
And the great truth is that the Spirit within us prays God's will. He teaches us God's will. He teaches us how to pray God's will. And He Himself prays God's will in us. And further that He seeks to pray God's will—that is to pray for the thing God has planned—in us before we have yet reached up to where we know ourselves what that will is.
We should be ambitious to cultivate a healthy sensitiveness to this indwelling Spirit. And when there comes that quick inner wooing away to pray let us faithfully obey. Even though we be not clear what the particular petition is to be let us remain in prayer while He uses us as the medium of His praying.
Oftentimes the best prayer to offer about some friend, or some particular thing, after perhaps stating the case the best we can is this: "Holy Spirit, be praying in me the thing the Father wants done. Father, what the Spirit within me is praying, that is my prayer in Jesus' name. Thy will, what Thou art wishing and thinking, may that be fully done here."