James 5:16: Confess your faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.
Romans 8:26: Likewise the Spirit also helpeth our infirmities: for we know not what we should pray for as we ought: but the Spirit itself maketh intercession for us with groanings which cannot be uttered.
1 Samuel 1:10, 13: (Hannah) . . . prayed unto the LORD, and wept sore. . . . 13 . . . she spake in her heart; . . .
Charles Haddon Spurgeon:
For real business at the mercy-seat give me a home-made prayer, a prayer that comes out of the depths of my heart, not because I invented it, but because God the Holy Ghost put it there, and gave it such living force that I could not help letting it out. Though your words are broken, and your sentences disconnected, if your desires are earnest, if they are like coals of juniper, burning with a vehement flame, God will not mind how they find expression. If you have no words, perhaps you will pray better without them than with them. There are prayers that break the backs of words; they are too heavy for any human language to carry.