Why should I be baptized?

Check out Romans 6:1-11. When you choose to go under the water, you identify with Christ who went into the grave. When you come up out of the water, you identify with His resurrection. Baptism signifies what has already happened to us spiritually. Our old identity as a sinner is gone, and we rise with a new identity in Christ. Baptism is an outward expression of an inward decision for Christ.