The Role of Prayer in God's Providence
"The prayer of a righteous person has great power as it is working" (v. 16b).
Calvinists are invariably forced to deal with certain questions that are raised by opponents of Reformed theology or by those who are trying to understand the system and evaluate it by Scripture. You have probably heard some of these questions or have asked them yourself. First there is the question of missions and evangelism: If God has elected only some for salvation, why should we evangelize? Are they not going to be saved anyway? Another common question concerns prayer: If the Lord has already ordained the outcome of all things, how can our prayers matter? Will God not do what He wants to do if we do not pray for it?
There are many answers to these questions, but there is one answer that addresses both issues. That is the reality that our Creator ordains the means as well as the ends. In an absolute sense, God certainly does not need our prayers or evangelism. The Lord is not "served by human hands, as though he needed anything, since he himself gives to all man-kind life and breath and everything" (Acts 17:25). Our Maker certainly could have chosen to work out the salvation of His people apart from our evangelism, and to bring things to pass apart from our intercession. However, that is not how He has ordinarily chosen to do things. He has purposed to save people through our preaching of the gospel and to show His mighty hand in answer to our prayers. That is a privilege He has granted to us. Prayer and evangelism are for our benefit, giving us a glorious purpose in the Lord's plan.
As to the question regarding whether prayer changes things, we must first note that prayer cannot change what God has ordained. By His hidden will, or His will of decree, He has already determined whatsover comes to pass, and this will is unalterable (Num. 23:19; Deut. 29:29). We live by His revealed will, that which He has said is in itself pleasing to Him (Deut. 29:29). It is not for us to figure out His hidden will, for we cannot know what He has not revealed. Instead, we are to take Him at His revealed Word, remembering, as He has told us, that "the prayer of a righteous person has great power as it is working" (James 5:16b). God has promised to work mightily in response to our prayers. He has revealed that He will use prayer to change not Himself, but to change things in fulfillment of His sovereign will. According to this verse, prayer does affect the course of our lives and the lives of others. Thus, we pray knowing that He works through our prayers to accomplish His purposes.
Coram Deo
In his Institutes, John Calvin notes that prayer is more for our benefit than it is for God's (3.20.3). While we can hold to the truth that there are some things that God will not do unless we ask Him (James 4:2b), we also know that even the prayers in which we ask of things from Him are ordained in His eternal plan. As we pray according to Scripture, we benefit, for we are conformed to the image of Christ and grow in our faith that He keeps all His promises.