A wonderful mystery of the historical Christian faith is the belief in the Trinity. We serve one God, yet, we also believe God is actually three, God the Father, God the Son, and God the Spirit. God is both one, and three at the same time. God the Father is the creator of the Universe. God the Son provides redemption by living as man, dying on the cross, and rising from the grave on the third day. God the Son sits at the right hand of the God the Father, and will return one day as judge, and all things will be placed at His feet. God the Spirit is the enabler. He enables us to have community with God the Father.
One of my largest frustrations with modern non-denominational Christianity is the effort to simplify that which is mysterious, especially with the Trinity. Modern non-denominational Christianity has led followers to believe a simplified monotheistic religion where “God=Christ, Christ=God”. The Spirit seems to be ignored or seen as a tool to achieve an end result.
In performing the sign of the cross across my chest, and saying “Father, Son, Holy Spirit”, I am regularly reminded of the wondrous mystery of the Trinity. This mystery reminds me that I am in a natural world, and it is impossible for me to understand all the mysteries of the super-natural world.