Here is the question and maybe someone has a good answer. Or I should say an answer through logic and reason? I am not sure. A question someone asked me and it made me think as I could not think of a good answer at the time. Here it is.
Hi “fjonc”

I’d be happy to share my opinions with you; but I guess you will have to be the judge of whether or not it is a “good answer”. Since you asked, specifically for “an answer through logic and reason”… I will start with faith… (which some might view as the opposite of logic and reason). But prayer, as I understand it… is an act of faith. The Catechism of the Catholic Church (CCC) states that faith is both a grace and a human act.
(156)"What moves us to believe is not the fact that revealed truths appear as true and intelligible in the light of our natural reason: we believe “because of the authority of God Himself Who reveals them, Who can neither deceive nor be deceived.”
God already knows what decisions we are going to make, down to what time we will be getting up in the morning, when we will die etc etc etc. Why do we pray then?
Prayer is the way in which we maintain a relationship with God. Jesus Himself, taught us to pray. And He prayed, to His Father… as many passages in the New Testament remind us. Just as a husband and wife, maintain a relationship… a dialogue with one another… (even though they know the next word or action of their beloved)… so we, maintain a relationship with God… through prayer.
Think of it this way. Would you even consider not speaking to your spouse? Or to your parents? Of course not!
CCC(2564) “Christian prayer is a covenant relationship between God and man in Christ. It is the action of God and of man, springing forth from the Holy Spirit and ourselves, wholly directed to the Father, in union with the human will of the Son of God made man.”
Why do we pray for someone who is sick and who is terminally ill? Why do we pray to make the right decisions in our lives. I understand there is free will involved. Still though God knowing what decision we are already going to make, why pray? Why pray that we will be able to do this or do that?
We pray for people who are sick, because it is an act of Christian Charity. We pray to make the right decisions in our lives as (again) an act of Faith. We pray for God’s assistance, His grace… to help us make the right decisions. Just because God already knows the outcome… doesn’t mean that we are “programmed” to any particular END.
CCC(600) “To God, all moments of time are present in their immediacy. When therefore He establishes His eternal plan of “predestination”, He includes in it each person’s free response to His grace.”
I hope that this is helpful to you. God bless.