I at one time thought baptism was purely symbolic, but after actually reading what the bible says about baptism I can no longer hold that theory:
*Galatians 3:27
for all of you who were baptized into Christ have clothed yourselves with Christ.
Acts 22:16
And now what are you waiting for? Get up, be baptized and wash your sins away, calling on his name.’
Romans 6:3-4
Or don’t you know that all of us who were baptized into Christ Jesus were baptized into his death? We were therefore buried with him through baptism into death in order that, just as Christ was raised from the dead through the glory of the Father, we too may live a new life.
Colossians 2:12
having been buried with him in baptism and raised with him through your faith in the power of God, who raised him from the dead.
1 Peter 3:21
and this water symbolizes baptism that now saves you also—not the removal of dirt from the body but the pledge of a good conscience toward God. It saves you by the resurrection of Jesus Christ,
Acts 2:38
“Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit”
John 3:5
Jesus answered, "I tell you the truth, no one can enter the kingdom of God unless he is born of water and the Spirit.*
Then, after finding out that the unanimous consent of the Early Church Fathers was that baptism was nessesary for salvation I knew that baptism wasn’t simply a symbol. Reason would also dictate that Christ wouldn’t give us a command to do something that wasn’t nessesary and had no effect on our salvation.