Describe who Mr. Merriweather is through an explanation of the paragraph in Chapter 24 of To Kill a Mockingbird.
"Mr. Merriweather, a faithful Methodist under duress, apparently saw nothing personal in singing, 'Amazing Grace, how sweet the sound, that saved a wretch like me...' It was the general opinion of Maycomb, however, that Mrs. Merriweather had sobered him up and made a reasonably useful citizen of him."
It is obvious that poor Mr. Merriweather is a hen-pecked husband, completely dominated by his wife, Grace--
"... certainly... the most devout woman in Maycomb."
Mr. Merriweather has no problems singing "Amazing Grace" because he can completely identify with the part about the sweet "sound, that saved a wretch like me." Mr. Merriweather had apparently been quite a drinker at some point before his wife "sobered him up," and he more than likely feels like a wretch married to such a woman. To the overly pious Mrs. Merriweather, her husband was not a fit man while drinking, but with her help, he was now a "reasonably useful citizen." Mrs. Merriweather is in complete charge of the women of the Missionary Circle, and she no doubt wears the figurative pants in her own family.