How can God be three Persons and one God at the same time? What is the Trinity?
Here's the answer:
God is 3 in 1.
God is three Persons: the Father, the Son, and the Holy Spirit. But He isn't three gods. When we say God is three Persons, we don't mean that He is three people or men. By "person," we mean that the Father, Son, and Spirit are real beings. Each is fully God. Each Person of God does different things, but all together they are one God. God is three in one, called the Trinity. The Trinity describes the three different Persons of our one God.
The Trinity is like water. Water can be a liquid, a solid (ice), or a gas (steam), but it's still only one thing—water. The Trinity is also like a family. A family can have a father, a mother, and a child, but it's still only one thing together—a single family. Of course, these examples can't fully explain the Trinity. God is greater than we can fully understand. The Trinity is hard to understand, but we believe it's true because God tells us He is three in one in the Bible.
"The Lord is our God. The Lord is one" (Mark 12:29b).
"May the grace of the Lord Jesus Christ, the love of God, and the fellowship of the Holy Spirit be with you all" (2 Corinthians 13:14).
"So you must go and make disciples of all nations. Baptize them in the name of the Father and of the Son and of the Holy Spirit" (Matthew 28:19).