And so, from the day we heard, we have not ceased to pray for you, asking that you may be filled with the knowledge of his will in all spiritual wisdom and understanding, so as to walk in a manner worthy of the Lord,fully pleasing to him, bearing fruit in every good work and increasing in the knowledge of God. May you be strengthened with all power, according to his glorious might, for all endurance and patience with joy, giving thanks to the Father, who has qualified you to share in the inheritance of the saints in light. He has delivered us from the domain of darkness and transferred us to the kingdom of his beloved Son, in whom we have redemption, the forgiveness of sins.
Colossians 1:9-14 (ESV)
Have you ever not known what or how to pray for someone? This is a perfect prayer for any Christian brother or sister. And remember that Jesus Himself is praying for his children. And the Holy Spirit prays for us "in accordance with the will of God". Romans 8:26-27