I’m not sure what Campbell has to do with this discussion, nor how he got brought into it.
I’m not “of Campbell” - nor of Stone, nor Calvin, nor Wesley, nor Luther, nor Graham, nor Pope So-and-So.
I am of Christ, Him having been crucified for me, and me having been baptized into His name (I Cor. 1:13).
Campbell was right insofar as he followed the Scriptures, and wrong insofar as he departed from them. The same is true for each one of us.
Are you departing from the Scriptures when you say the Bible requires that one be baptized only by a Christian? Where can I read that for myself?
You can read that for yourself in Matthew 28:16-20.
When one follows the teachings of a 19th century false prophet as opposed to the Apostolic Faith, one is of that person whether they want to admit it or not.