When I am angry I can pray well and preach well.

To pray well is the better half of study.

Grant that I may not pray alone with the mouth; help me that I may pray from the depths of my heart.

Prayer is climbing up into the heart of God.

Prayer, study, and suffering make a pastor.

As is the business of tailors to make clothes and cobblers to make shoes, so it is the business of Christians to pray.

It is a tremendously hard thing to pray aright, yea, it is verily the science of all sciences.