From Don Green:
Christian friends, what follows from Martin Luther is a critical principle to grasp for your spiritual growth.
The power of prayer is not found in your flawed devotion, effort, eloquence, or many words.
Christ alone is the basis upon which our prayers are heard.
That frees you to speak plainly and directly in the presence of God.
Better to pray five words humbly trusting in the name of Christ than to follow the human rules of 5000 prayer conferences.
And now from Luther. Long live biblical truth. Long live the Reformation:
"Some fail disastrously in prayer. They nullify it, for they utter it merely with their lips and not with their hearts. They will not believe that they are heard until they imagine that they have prayed well and worthily. Thus they build on themselves.
"A prayer is not good because of its length, devoutness, sweetness, or its plea for temporal or eternal goods. Not your zeal, but [Christ and] God's Word render your prayer good.
"Only that prayer is acceptable which breathes a firm confidence and trust that it will be heard because of the reliable pledge and promise of God [found in Scripture alone]."
~ Martin Luther
"And when you are praying, do not use meaningless repetition as the Gentiles do, for they suppose that they will be heard for their many words. So do not be like them; for your Father knows what you need before you ask Him” (Matthew 6:7-8).