Faith is not symbolic but baptism is clearly symbolic of the fact that the believer died, was buried, and rose again with Christ in order to walk in newness of life. So if someone says that it is the outward expression of an inward reality, then that too is acceptable.
Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death?
Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection: (Rom 6:3-5).
That word "likeness" indicates symbolism.