Jonathan Edwards discusses the importance of sincerity in our speech and the nature of language, and its importance especially when the church is gathered together.

If a man goes about to declare or profess any particular thing by words which have no distinguishing signification, or without any signs or discriminating marks by which men may be enabled to distinguish what he means, his words are vain to the pretended purpose, and wholly fail of answering the end of words, which is to convey the thing meant to others’ understanding, or to give notice to others of the thing that is to be supposed or understood.

Therefore to use words thus in common conversation, is to act in a vain, trifling manner, more like children than men: but to use words thus in the sacred services of God’s house, and solemn duties of his worship, is something much worse than children’s play. (Misrepresentations Corrected, Works 12:389)