After being baptized, Jesus came up immediately from the water; and behold, the heavens were opened, and he saw the Spirit of God descending as a dove and lighting on Him, and behold, a voice out of the heavens said, “This is My beloved Son, in whom I am well-pleased.”
Matthew 3:16-17
The above passage is taken from Jesus’ baptism and it is one of the more concise passages in which to demonstrate the tri-une nature of God. Jesus, the Word become flesh, God the Son is baptized in the physical river, as God the Spirit descends him “as a dove” the Scriptures say, while God the Father speaks over Him from heaven, calling Him His Son. God the Father is in heaven, and He is sending God the Spirit upon His Son, who is also God.
Here, we see the three persons of the one God in different ways.