Why did Theodore Parker die? He died prematurely worn out through this enormous activity, -- a warning, as well as an example.... Had he been a mere student, this had been less destructive. But to take the standard of study of a German professor, and superadd to that the separate exhaustions of a Sunday preacher, a lyceum lecturer, a radical leader, and a practical philanthropist was simply to apply half a dozen distinct suicides to the abbreviation of a single life. And as his younger companions had long assured him, the tendency of his career was not only to kill himself, but them; for each assumed that he must at least attempt what Theodore Parker accomplished.... [Thomas Wentworth Higginson]
There were quite a few 19th century Unitarian ministers whose exhausting work was felt to have contributed to their premature demise, Joseph Stevens Buckminster and Henry Ware Jr. to name only two. But Parker's persona as a constitutionally robust child of farmers was a sharp contrast to the frail, "spiritual" ectomorphic body-types generally associated with piety in that era.
More to the point though is Higginson's observation that for many of the generation of clergy who followed Parker, the challenge of his accomplishments as Preacher and Abolitionist Reformer, Scholar, Lecturer, "Practical Philanthropist" (a reference to Parker's active involvement in hands-on public/pastoral ministry as well his more radical political involvement), and general all-around busybodyness set an impossibly high standard, while implicitly encouraging neglect of many of the more run-of-the-mill institutional duties of parish ministry.
Yet even recognizing this, we still admire him to this day as one of the "Three Prophets" of Religious Liberalism. We point to the 28th Congregational Society as some sort of great institutional success, the 19th century equivalent of the modern Megachurch, and...
Let me just say this. There's a lot more to "the Golden Age of Unitarianism" that Parker, Emerson, and Channing. But most of us seem hard pressed even to understand them in their context. And so we find ourselves trapped by a form of idolatry, flirting with "half a dozen distinct suicides" as we attempt to minister effectively in our time and place based on a false knowledge of our past, and a mistaken understanding of our real charge.
And yes, I still adore Theodore Parker....