One of the many indictments brought against those who affirm the doctrines of grace (the five points of Calvinism) is that it makes prayer unnecessary. Why pray if God has already predestined everything to happen? Doesn’t prayer make much more sense with a God who is less controlling than the God of Calvinism? John Piper explains how God’s sovereignty not only is compatible with our prayers, but makes our prayers possible.
Why Do Calvinists Pray? (Video)
Marc Sims 
How much I needed to hear this only God knows! This quote is priceless: “Watch out that you don’t use logic to silence the Bible! The Lord of the Harvest says ask Me to put laborers in the harvest. We say, ‘why????'” May God forgive us!