” Pope Innocent III wrote in his instructions on making the Sign of the Cross. Holding two fingers together—either the thumb with the ring finger or with index finger—also represents the two natures of Christ. This is also reinforced by using three fingers to make the sign, according to Pope Innocent III.
Ultimately by tracing the sign of the cross we are recalling Christ’s passion on the crucifixion. Thus we are affirming our belief of the Holy Trinity. When we appeal to the trinity, we fix our attention to God who made us.
Philippians 2:10, St. Paul tells us that “at the name of Jesus every knee should bend, of those in heavens and on earth and under the earth.”
John 14:13-14, Jesus Himself said, “And whatever you ask in my name, I will do, so that the Father may be glorified in the Son. If you ask anything of me in my name, I will do it.”