If God has sovereignly predestined everything, why do we need to pray? Does Prayer change things?

It is true that from a certain stand-point, prayer does not change anything seeing that God has decreed all things from eternity past. But this does not mean that prayer is unnecessary. Let me give just four simple reasons:

(1) We must pray because we are commanded to pray. This is the clearest and foremost reason why we ought to pray. We may not understand fully what prayer does, but it is enough that we are commanded to pray. The Lord urges us through Jeremiah: "Call unto me, and I will answer thee, and shew thee great and mighty things, which thou knowest not" (Jer 33:3). And Jesus taught that "men ought always to pray, and not to faint" (Lk 18:1). And He encourages: "Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you" (Matt 7:7). He Himself prayed fervently, and He gave His disciples and us a pattern of prayer. Not only so, He gently chided His disciples for not praying and so missing out on what blessings may be theirs: "Hitherto have ye asked nothing in my name: ask, and ye shall receive, that your joy may be full" (Jn 16:24). Similarly the apostle Paul instructs us: "Pray without ceasing. In every thing give thanks: for this is the will of God in Christ Jesus concerning you"" (1 Thes 5:17-18).

(2) We must pray because it is appointed for our physical and spiritual blessings. As we pray, we learn to flee to God as our ever present Help, our Provider and Sustainer. So the Apostle Peter urges us to cast our anxiety upon Him because He cares for us (1 Pet 5:7). Although God knows all our needs (Matt 6:32), He appointed prayers that we may know we are needy creatures and so learn to depend on Him. Thus we may say that though prayer may not change anything else, it changes us. To this end, John Calvin, responding to the objection that God is omniscient and therefore does not requires our prayer, urges:

…it is very important for us to call upon Him: First, that our hearts may be fired with a zealous and burning desire ever to seek, love, and serve Him, while we become accustomed in every need to flee to Him as to a sacred anchor. Secondly, that there may enter our hearts no desire and no wish at all of which we should be ashamed to make Him witness, while we learn to set all our wishes before His eyes, and even to pour out our whole hearts. Thirdly, that we be prepared to receive His benefits with true gratitude of heart and thanksgiving, benefits that our prayer reminds us come from His hand [cf. Ps 145:15-16]. Fourthly, moreover, that, having obtained what we were seeking, and being convinced that He has answered our prayers, we should be led to meditate upon His kindness more ardently. And fifthly, that at the same time we embrace with greater delight those things which we acknowledge to have been obtained by prayers. Finally, that use and experience may according to the measure of our feebleness, confirm His providence, while we understand not only that He promises never to fail us, and of Hid own will opens the way to call upon Him at the very point of necessity, but also that He ever extends His hand to help His own, not wet-nursing them with words, but defending them with present help. (ICR 3.20.3)

(3) We must pray because God is greatly honoured and glorified in our prayers. As we pray, we recognise that our relationship with Him is one of creature to Creator and subject to Sovereign. We learn to depend on Him constantly as our Heavenly Father and Benevolent King. Prayer moreover is not only that of supplication but of thanksgiving and ascription of praise. Thus the Lord said: "Whoso offereth praise glorifieth me" (Ps 50:23). The Psalmist teaches us: "Praise ye the LORD. O give thanks unto the LORD; for he is good: for his mercy endureth for ever" (Ps 106:1).

(4) We must pray because God’s sovereign decrees include our prayers. If God has foreordained all things (Heb 1:3; Matt 10:29-30 etc.), it is clear that even our prayers are foreordained. Thus the Psalmist confess: "For there is not a word in my tongue, but, lo, O LORD, thou knowest it altogether" (Ps 139:4). While our prayers do not change God’s eternal decrees, it is helpful for us to realise that they are covered in His decrees and are the providential outworking of the decrees. Rev 8:1-5 illustrates this point in that there was silence in heaven until the prayers of the saints ascended to God. In other words, in a certain sense, prayer has been ordained of God as a means to various ends in accordance with His secret will. So then, prayer is a mystery. Though God has predestined all things, he gives us the privilege and responsibility to prayer and so participate, as it were, in the course of providence.a