Baptism is not a symbol, it is a sacrament.  Meaning, it has spiritual ramifications in the heavenly realm. When we were Baptized, Paul says we were baptized into his death, burial and resurrection.  And because we died with Christ, we also rose victorious with him.  And just as sin has no mastery over Jesus, it no longer has mastery over us.  Just as Jesus is free to live fully to God, we too are now free to live fully to God.