I really mean it. Pray as though you actually believed in the doctrine of the Trinity. Why do I say this? Well, two times in this past week, worship leaders at chapel and at church prayed in a non-Trinitarian fashion. While addressing the prayer to God the Father, they mistakenly said that he had taken on flesh and died on the cross! This is an ancient heresy called patripassianism (or modalism), which (according to Wikipedia) states that “God the Father, Jesus Christ, and the Holy Spirit are three different modes or aspects of one monadic [one-personed] God, as perceived by the believer, rather than three distinct persons within the Godhead.” It was called “patripassianism” (from the Latin patri- “father” + passio “suffering”) because this doctrine required that God the Father be the one suffering on the cross since he had taken on flesh.
Think of it like water: it is sometimes liquid, other times solid (ice), and other times gas (water vapor), but it is never all three at the same time. Water simply moves between these three modes of existence. That is the modalistic conception of God.
This is erroneous according to orthodox Trinitarian theology; the Bible is clear that the Son, the Word, was the one who became flesh (John 1:14), not the Father. At Jesus’ baptism, the Father declares that Christ was his “beloved Son,” and the Holy Spirit descended upon him (Matt. 3:16-17). We see clearly that the Father and the Son and the Spirit are distinct from each other, and not the same person. However, the Father, Son, and Spirit are all called “God” on numerous occasions. God is one in being (or substance; hence, the creedal language of God the Son being of one substance with the Father) but three in person. We are not polytheists, but trinitarian monotheists.
I’m not trying to accuse those leaders of heresy; far from it. I’m simply exhorting all of us to be more careful in our prayers. Many of us mistakenly pray modalistically, and that ought not be so. We must be functionally Trinitarian, living our Christian lives and praying as though we actually believed that God eternally exists in one being and three persons, the Father, Son, and Holy Spirit. God the Father did not come down to earth and die on the cross; God the Son did.