In those days Jesus came from Nazareth in Galilee and was baptized by John in the Jordan. And immediately coming up out of the water, He saw the heavens opening, and the Spirit, like a dove, descending upon Him; and a voice came from the heavens: “You are My beloved Son; in You I am well pleased.”
-Mark 1:9-11
Why Baptism?
Choosing to accept God's gift of salvation is a private decision between you and God. Baptism is a public statement showing the world your decision.
As Jesus showed on the cross when ministering to the prisoner beside Him, we don't have to be baptized to be saved. Instead, baptism is a symbol of what happens when a person chooses to follow Christ. Some old pastors used to say "buried with Him in baptism, raised to walk in the newness of life" as they performed a baptism. It was their way of reminding us how the water represents a grave where the old person is buried and a new person emerges to walk in the ways of Christ. Meanwhile, other denominations insist that the water must be flowing, because it represents the washing away of sins.
The who, what, where, when and how of your baptism isn't nearly as important as the why. Baptism is the first step of obedience. Salvation is a decision to accept a gift and live a life dedicated to following Jesus. Baptism turns those thoughts and words into actions. When Jesus called His apostles to follow Him, they each had to make a decision to follow, but they also had to take the first step on a longer journey.