14:15-25 There can be no assent to prayers that are not understood. A truly Christian minister will seek much more to do spiritual good to men's souls, than to get the greatest applause to himself. This is proving himself the servant of Christ. Children are apt to be struck with novelty; but do not act like them. Christians should be like children, void of guile and malice; yet they should not be unskilful as to the word of righteousness, but only as to the arts of mischief. It is a proof that a people are forsaken of God, when he gives them up to the rule of those who teach them to worship in another language. They can never be benefitted by such teaching. Yet thus the preachers did who delivered their instructions in an unknown tongue. Would it not make Christianity ridiculous to a heathen, to hear the ministers pray or preach in a language which neither he nor the assembly understood? But if those who minister, plainly interpret Scripture, or preach the great truths and rules of the gospel, a heathen or unlearned person might become a convert to Christianity. His conscience might be touched, the secrets of his heart might be revealed to him, and so he might be brought to confess his guilt, and to own that God was present in the assembly. Scripture truth, plainly and duly taught, has a wonderful power to awaken the conscience and touch the heart.
25. And thus—omitted in the oldest manuscripts and versions.
secrets of his heart made manifest—He sees his own inner character opened out by the sword of the Spirit (Heb 4:12; Jas 1:23), the word of God, in the hand of him who prophesieth. Compare the same effect produced on Nebuchadnezzar (Da 2:30 and end of Da 2:47). No argument is stronger for the truth of religion than its manifestation of men to themselves in their true character. Hence hearers even now often think the preacher must have aimed his sermon particularly at them.
and so—convicted at last, judged, and manifested to himself. Compare the effect on the woman of Samaria produced by Jesus' unfolding of her character to herself (Joh 4:19, 29).
and report—to his friends at home, as the woman of Samaria did. Rather, as the Greek is, "He will worship God, announcing," that is, openly avowing then and there, "that God is in you of a truth," and by implication that the God who is in you is of a truth the God.