Below are five statements from John Piper as a summary theology of prayer. An assumption behind these statements is that to know more of God's purpose will deepen our commitment to pray and help us glorify God for why he does what he does.
1. God created the universe and all that is in it to display the riches of the glory of his grace.
Isaiah 43:6-7: Bring my sons from afar and my daughters from the end of the earth, 7 everyone who is called by my name, whom I created for my glory, whom I formed and made."
Ephesians 1:6, 12, 14: to the praise of his glorious grace…to the praise of his glory…to the praise of his glory.
Romans 9:23: …in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory.
2. Therefore all persons should act in a way that calls attention to the glory of God's grace.
Matthew 5:16 In the same way, let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven.
1 Corinthians 10:31 So, whether you eat or drink, or whatever you do, do all to the glory of God.
3. The obedience and service of God's people will glorify him most when they consciously and manifestly depend on him for the grace and power to do what they do.
1 Peter 4:11 Whoever speaks [must do so] as one who speaks oracles of God; whoever serves, as one who serves by the strength that God supplies-in order that in everything God may be glorified through Jesus Christ. To him belong glory and dominion forever and ever. Amen.
2 Thessalonians 1:11-12: To this end we always pray for you, that our God may make you worthy of his calling and may fulfill every resolve for good and every work of faith by his power, 12 so that the name of our Lord Jesus may be glorified in you, and you in him, according to the grace of our God and the Lord Jesus Christ.
4. Prayer for God's help is one way that God preserves and manifests the dependence of his people on his grace and power. The necessity of prayer is a constant reminder and display of our dependence on God for everything, so that he gets the glory when we get the help.
Psalm 50:15: Call upon me in the day of trouble; I will deliver you, and you shall glorify me.
John 14:13 Whatever you ask in my name, this I will do, that the Father may be glorified in the Son.
5. When the Spirit inspires and directs the groanings in our hearts, the ultimate purpose of the universe happens: God gets the glory because God the Spirit creates the groanings in us; God gets the glory because God the Father is the one who hears and performs what the Spirit asks; God gets glory because God the Son purchased for sinners every blessing they ever receive; and God gets glory because our hearts are made the theater for this divine activity, so that we know and experience God's gracious intercession for us and consciously give him thanks and praise.