Someone at work or school stops you: “Hey, you’re a Christian. I heard God being three persons yet one God is just a New Testament thing made up by Christians. Where is God as three yet one in the Old Testament?” 

What do you do? Run away. Stare blankly forward until the person walks away. Those are options. This explanation is better! 

In Deuteronomy 6:4, God defines himself as ONE: “Here, O Israel: The Lord our God, the Lord is one.” In Genesis 1:26, God refers to himself in the plural, hinting at being three persons: “Let us make mankind in our image, in our likeness.” Then in Numbers 6:24-26, God narrows down his plural nature into three: “The Lord bless you and keep you; the Lord make his face shine on you and be gracious to you; the Lord turn his face toward you and give you peace.” There are THREE “the Lords.” Father. Son. Holy Spirit. Here God gives the job description of each person of the Trinity. The Father blesses and keeps you as an earthly father should and as your heavenly Father does. The second “the Lord” is Jesus, who pours grace and forgiveness into your life. The last “the Lord” is the Spirit, who brings you to faith, resulting in peace being in your life. 

Father, Son, and Spirit, since before creation, throughout the Old Testament and throughout your life, rule and reign over your life. What comfort to know he always was, is, and will be!