Romans 6:4 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. 5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
Matthew 26:28 For this is my blood of the new testament, which is shed for many for the remission of sins.
Baptism just like the Protestant communion are a spiritual exercises. It is not the water that cleanses any more then the bread and wine physically become the body and blood of Jesus. They are in both cases the spiritual equivalent of being cleansed by the blood and partaking of the flesh and blood of Christ.
Do we need to be baptized? Yes, it’s a spiritual exercise of being cleansed by the blood. We walk in the spirit not in the flesh.
Those observances have their place as we tend to be a forgetful ungrateful bunch, we humans.
It’s a great picture and reminder of what Christ has done for us. It’s an outward profession to the great cloud of witnesses which encompasses us and an outward testimony to a lost and unbelieving world of the inward faith we exercised and inward reality we have experienced.