Luther on the Gift of Prayer for the Christian:
This is a miserable world for unbelievers. They work so hard, yet accomplish nothing. They may even pray a lot, search all over, and knock at the door. Yet nothing is gained, found, or achieved, for they’re knocking on the wrong door.
They do all these things and even pray as if they were doing any other work. In other words, they do all this without any faith. That’s why they can’t really pray.
Prayer is the work of faith alone. No one, except a believer, can truly pray. Believers don’t pray on their own merits, but in the name of the Son of God, in whom they were baptized.
They’re certain that their prayers please God because he commanded them to pray in the name of Christ and promised he would listen to them. But the others don’t know this. Instead, they pray in their own name and believe they can prepare themselves....
But Christians pray in response to God’s command and promise. We offer our prayers to God in the name of Christ, and we know that what we ask for will be given to us. We experience God’s help in all kinds of needy situations.
And if relief doesn’t come soon, we still know that our prayers are pleasing to God. We know that God has answered us because he gives us the strength to endure.
- LW, AE 14:47, as found in By Faith Alone