When you don't know what to pray, read the Bible. Scripture shows God's will and gives you specific language for prayer: ask for patience, joy, trust. The Word ignites prayer by fueling passion and intensity.
When you don't know what to pray, open the Word. 1 John 5:14 says, this is the confidence we have in approaching God, that if we ask anything according to His will, He hears us. The Word of God is His will. When you read Scripture, you see His promises, you see His commands, you see what He wants for your life, and suddenly you have language for prayer. Lord, give me patience where I've been impatient. Lord, give me joy where I've been burdened. Lord, help me trust where I've been fearful. The Word becomes fuel for prayer, depth prayer, passion for prayer. The Word ignites the fires of prayer.
