The bible NEVER tells us baptism is symbolic. This is what the bible tells us baptism is:
The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ:
This is the Greek word used there for answer:
eperótéma: an inquiry, a demand
Original Word: ἐπερώτημα, ατος, τό
Part of Speech: Noun, Neuter
Transliteration: eperótéma
Phonetic Spelling: (ep-er-o'-tay-mah)
Definition: an inquiry, a demand
Usage: inquiry, request, appeal, demand; a profession, pledge.
Can you point to a passage where there is any other way to appeal to God for a good conscience? i.e. the "sinners prayer"