Since God knows everything, why does God tell us to even pray?
God is omniscient, so he absolutely knows what we will pray before we even think and voice our prayers (Matt. 6:8). But he still has us say them. It is for our benefit. It’s a step of faith without which we can’t please God (Heb. 11:6).
God also has us pray because he uses such as secondary causes (WCF 5.2, 3; 1689 BCF 5.2, 3).
Before getting into secondary causes, let's first understand that God is the First Cause — the primary causation of all that comes to pass. In his sovereignty, God immutably decreed (past tense) all things that definitely will come to pass. As Isaiah 46:9-10 states:
Remember the former things of old; for I am God, and there is no other; I am God, and there is none like me, declaring the end from the beginning and from ancient times things not yet done, saying, ‘My counsel shall stand, and I will accomplish all my purpose.
Now, secondary causes are anything in the created order appointed by God to produce effects in a specific way for his own glory. An example (paraphrased) from my seminary experience may help.
If I build a wooden chair, I’m the primary cause of the chair. But there are also some secondary causes of the chair being built, like a hammer, nails, glue, a saw, etc. Without these materials, I couldn’t build the wooden chair.
God uses secondary causes to accomplish his primary causes. These are part and parcel of his eternal decrees. And to his glory, he uses created things so that everything is both a product of his work and a product of his own creation.
There are three types of secondary causes: necessary, free, and contingent. A necessary cause is like the sun and the rotation of the earth. This is necessary to sustain all life. A free secondary cause is like a brick dropping from the top of the Empire State Building and "accidentally" hurting someone below. Contingent means occurring only if particular circumstances exist. For instance, when we pray, "Thy will be done," we make our prayers contingent on and dependent upon God’s will. In others words, we are asking our prayers to be answered as much as they agree with God’s will and pleasure.
Prayers aren’t only a step of faith towards and with Almighty God. They are a reminder of who he truly is. He is the sovereign, covenant-loving, listening, caring God that faithfully answers prayer! We need to be continuously reminded of this (cf. 2 Pet. 1:12-15; 3:1).
Dr. Joseph R. Nally, Jr., D.D., M.Div. is the Theological Editor at Third Millennium Ministries (Thirdmill).