I just ran across a quote in the great book that John Nugent edited, Radical Ecumenicity.
Barton Stone said, "None of us are disposed to make our notions of baptism, however well founded, a bar of christian fellowship. We acknowledge all to be brethren, who believe and obey the Saviour, and, who walking in the Spirit, bear his holy image; yet, in the meekness of Christ, we labor to convince such of their duty in submitting to every ordinance of the Lord."
Moses Lard who preached in the 1860s expressed another view. "I mean to say distinctly and emphaticaly that Martin Luther, if not immersed, was not a Christian...If a man can be a Christian without immersion, let the fact be shown; or if a man can or may commune without being a Chrsitian, let the fact be shown. I deny both. Immovably I stand here. But I shall be told that this is Phariseeism, that is exclusivism. Be it so; if it be true...then am I so far the defendant of Phariseeism and exclusivism."