Now, I don’t make much of this, but it seems to me like a bit of bogus etymology. “Protest” might be the nearest cognate of “Protestant” in modern English, but it’s silly to take that as a clue to the word’s origin –sort of like finding “dance” in the word “concordance” and deciding they’re related; or “sacrilege” means putting religion in a sac; or that “validate” is from valid + date = “at the right time;” or “excruciate” means to take off of a cross, etc. But I digress.
The word seems to come from pro + testari, to testify forth, or to hold forth a position on something. Its primary historical meaning has been to assert, to maintain, to proclaim solemnly or state formally.
You can find the positive sense of Protestant all over early English literature. Perhaps the best example is from the poet Robert Herrick (1591-1674), whose poem “To Anthea, who may command him anything” begins:
BID me to live, and I will live
Thy Protestant to be;
Or bid me love, and I will give
A loving heart to thee.
and ends:
Thou art my life, my love my heart,
The very eyes of me:
And hast command of every part
