Three in one?
How can God the Father, Son, and the Holy Spirit be together as one? When Jesus was baptized, God spoke from above and a dove came and perched on his shoulder. How did he do that?
The Bible tells us that there is one God and that there are three persons.
How this can be we do not know and cannot explain. It is not a matter of mathematics or human logic, but a mystery. Remember that in the creeds we do not say, “We understand.” Instead we say, “We believe.”
By the same token, we do not know how God did what he did at Jesus’ baptism. We only know from Scripture that he did it. This is true of much that God has done and that he does now.
The most important thing for you and me to remember about the Trinity is that God sent his Son to save us, that the Son did that, and that the Holy Spirit uses Word and sacrament to create and preserve faith in us.