Harry: Christopher can scoff, Jack, but I know how hard you've been praying; and now God is answering your prayers.
C. S. Lewis: That's not why I pray, Harry. I pray because I can't help myself. I pray because I'm helpless. I pray because the need flows out of me all the time, waking and sleeping. It doesn't change God, it changes me.
Anthony Hopkins portraying C.S. Lewis in the movie Shadowlands explains to his friend why he prays.
A question I have been asked a few times through the years, and that I must address as a father is, "Why do we pray?" Of course there are books written on the subject, but I have a few ideas that I generally share.
pray without ceasing, give thanks in all circumstances; for this is the will of God in Christ Jesus for you. 1 Thessalonians - 5:17 ESV
Pray then like this: “Our Father in heaven, hallowed be your name. Your kingdom come, your will be done, on earth as it is in heaven. Give us this day our daily bread, and forgive us our debts, as we also have forgiven our debtors. And lead us not into temptation, but deliver us from evil. - Matthew 6:9-13 ESV
If any of you lacks wisdom, let him ask God, who gives generously to all without reproach, and it will be given him. But let him ask in faith, with no doubting, for the one who doubts is like a wave of the sea that is driven and tossed by the wind. - James 1:5-6 ESV
But seek first the kingdom of God and his righteousness, and all these things will be added to you. - Matthew 6:33 ESV
Note that I am providing a single verse as a jumping off point, but there are multiple verses for each of these concepts. Always look for verses. If you have a single verse to support a particular theological position it quickly becomes problematic.
When I wrote the first part of these thoughts almost a decade ago, a friend responded with a good point when he said, "I think it might also be helpful to explore why we don't pray." Here are a few possible reasons why we do not pray.
Just to add a personal level to the discussion (not that there is likely to be one), I pray very short prayers, and not many of them. My primary reasons are doubts and guilt. It is indeed unfortunate that humans have a proclivity for knowing what is right, and yet ignoring it.
Obviously, if you are not a follower of Christ you are welcome to add your thoughts, but I am not particularly interested in Christian apologetics at this point. This is geared basically toward those that are followers of Christ or are interested in theology proper in general.