[Biblestudent]

Brother Tony,
The "one" there is not QUANTITY but QUALITY.

There is ONE true Lord, but there are OTHER lords.
There is ONE true Spirit, but there are OTHER spirits.
There is ONE faith that is essential -- the "faith of Christ"; but there are OTHER "faiths".
Etc.

There is ONE real baptism that saves today, the baptism by "one Spirit into the body of Christ"; but there are OTHER "baptisms".

Remember, when Paul said 1 Corinthians 12:13 and 1 Corinthians 1:17, he was water baptizing at the same time.