The Trinity is the greatest mystery ever revealed to humanity. Even the great St. Augustine devoted years to studying and writing On the Trinity (De Trinitate), one of the most influential theological works in Christian history. Yet despite his brilliant intellect, Augustine recognized that the human mind could never fully comprehend the mystery of God. As he famously stated, “If you understand God, what you understand is not God.” It is therefore fitting that no human explanation can completely capture the Trinity. We were created to know God and enter into a relationship with Him, not to fully grasp the infinite mystery of His divine nature.
Nevertheless, God has revealed this truth about Himself: He is one in divine nature and three in divine Persons—the Father, the Son, and the Holy Spirit.
Every time Catholics make the Sign of the Cross, we proclaim this central mystery of our Faith. This simple gesture is far more than a religious habit or cultural tradition. It is a profession of faith in the Triune God and an invitation to enter into His presence. We are not merely sending positive energy into the universe, practicing optimistic thinking, or invoking a vague spirituality. Rather, we are speaking directly to the living God. We begin our prayers by invoking the Father, the Son, and the Holy Spirit because Christian prayer is a personal encounter with the God who created us, redeemed us, and knows each of us by name.
When we speak to someone we love, we call that person by name because names express identity and relationship. Calling someone by name is an act of respect and love. How much more, then, should we reverently call upon the holy name of God when we enter His presence in prayer?
The Sign of the Cross also reveals the beautiful continuity between the Old and New Covenants. Jesus, Mary, and Joseph were faithful Jews who prayed the Shema, Israel’s great profession of faith:
Hear, O Israel: The Lord our God, the Lord is one. You shall love the Lord your God with all your heart, with all your soul, and with all your strength. (Dt. 6:4–5)
When Jesus was asked which commandment was the greatest, He answered by quoting the Shema (Mk. 12:29–30). He did not abolish Israel’s confession that there is one God; rather, He affirmed it as the foundation of the spiritual life.
What Jesus revealed, however, is that the one God has made Himself known more fully than anyone could have imagined. Throughout His public ministry, Jesus spoke of the Father who sent Him into the world, declared, “I and the Father are one” (Jn. 10:30), and promised to send the Holy Spirit to guide His disciples into all truth (Jn. 16:13). At His baptism, the Father spoke from heaven, the Son stood in the waters of the Jordan, and the Holy Spirit descended like a dove, revealing the three divine Persons without compromising the oneness of God (Mt. 3:16–17).
The Gospel does not replace the Shema. Rather, Jesus affirms its proclamation that the Lord is one while revealing the mystery of God’s inner life. Through Christ, we come to know the one God as Father, Son, and Holy Spirit. God’s unity is a perfect communion of divine love.
Every time Catholics make the Sign of the Cross, we proclaim both the oneness of God confessed by Israel and the fullness of God’s self-revelation in Jesus Christ. This same Faith is proclaimed more fully in the Apostles’ Creed and the Nicene Creed. For this reason, the Sign of the Cross is often described as “the Creed in miniature.” In one simple gesture, Catholics confess the central mystery of Christianity before a single word of prayer is spoken.
There is also a beautiful devotional connection between the Shema and the movements of the Sign of the Cross. The Shema calls us to love God with our entire being. As we trace the cross upon ourselves, we can reflect upon those words:
- With all your mind: As we touch the forehead, we dedicate our thoughts and intellect to God.
- With all your heart and soul: As we touch the chest, we offer Him our love, desires, and entire lives.
- With all your strength: As we touch each shoulder, we commit our actions, work, sacrifices, and burdens to His service.
The next time you make the Sign of the Cross, do not rush through it. Pause and remember the prayer Jesus Himself prayed and the commandment He called the greatest. As your hand moves from your forehead to your heart and then from shoulder to shoulder, renew your desire to love the Lord your God with all your mind, all your heart, all your soul, and all your strength.
Photo by Alessandro Sarno on Unsplash
