It’s one thing to acknowledge Jesus as your Savior. It’s another to bow your knee to Him as King.
The first is important—we begin to realize our hopeless situation, and reach out for the hand that has been stretched out for us all along.
The second, however requires us to give away our lives, to be known as nothing more than His subjects—to desire what He desires—to do what we should do. This is called sanctification, and every Christian must go from being simply “saved” people to being also “kingdom” people.