Evagrius Ponticus

If you wish to pray, you have need of God, “who gives prayer to him who prays.” Invoke him, then, saying, “Hallowed be thy name, thy kingdom come”49—that is, the Holy Spirit and your only begotten Son. For this is what he taught us, saying, “Worship the Father in spirit and in truth.” He who prays in spirit and in truth is no longer dependent on created things when honoring the Creator but praises him for and in himself. If you are a theologian, you will pray truly. And if you pray truly, you are a theologian.