Nothing symbolic about water baptism described here.
Believers simply have t o be dead to sin.
Dying to sin is not a deed or action enabled by water baptism. Baptism is a public witness, not an enabling mechanism. Some believers do indeed lived in sin after water baptism, due to weakness, falling away from the body of Christ. Some are even pretenders, secretly steeling into the church to spy out christian joy and freedom. Christian audience of Romans knew the truth, although the mode of baptism is not clearly stated in the bible.