In the Gospel Jesus referred to his upcoming death as “a baptism with which I must be baptized.” It was, of course, his death that he was referring to as a baptism.
It might help us to turn that around: to see our baptisms as a form of death. I know you are well aware of what I am about to tell you, but it might be useful for us to think over it again.
In the first century Baptism was conferred only on the Saturday of Holy Week. And it was seen as our way of joining in the death of Jesus. On that day the first Christians thought of Jesus as dead in the tomb, awaiting resurrection. They stood around a pool of water that for them symbolized the tomb of Jesus. They had in mind something Paul said, namely, Our Lord saved us not so much by his physical death, but by his “death to sin.”
They saw taking the plunge into the baptismal pool as a symbolic way of saying they were joining Jesus in his death to sin.
That was long ago, but things haven’t changed all that much. Whatever might be in our minds at the time of our baptisms, the ritual itself retains its original meaning. It is our pledge to die to sin. We must spend our lives living up to that pledge.