Peter's Scripture quotations were apt, fitting the occasion and the people to whom they were addressed. The testimony was bold and joyous, the rushing outflow of a warm, fresh throbbing experience; and the exhortation was burning, uncompromising in its demands, and yet tender and full of sympathy and love. But a Divine Presence was at work in that vast, mocking, wondering throng, and it was He who made Peter's simple words search like fire, and carry such overwhelming conviction to the hearts of the people. And it is still so that whenever and wherever a man preaches "with the Holy Ghost sent down from Heaven," there will be conviction. Under Peter's sermon "they were pricked in their hearts." The truth pierced them as a sword until they said, "What shall we do?" They had been doubting and mocking a short time before, but now they were earnestly inquiring the way to be saved. The speech may be without polish, the manner uncouth, and the matter simple and plain; but conviction will surely follow any preaching in the burning love and power and contagious joy of the Holy Spirit. A few years ago a poor black boy in Africa, who had been stolen for a slave, and most cruelly treated, heard a missionary talking of the indwelling of the Holy Spirit, and his heart hungered and thirsted for Him. In a strange manner he worked his way to New York to find out more about the Holy Spirit, getting the captain of the ship and several of the crew converted on the way. The brother in New York to whom he came took him to a meeting the first night he was in the city, and left him there, while he went to fulfil another engagement. When he returned at a late hour, he found a crowd of men at the penitent-form, led there by the simple words of this poor black fellow. He took him to his Sunday-school, and put him up to speak, while he attended to some other matters. When he turned from these affairs that had occupied his attention for only a little while, he found the penitent-form full of teachers and scholars, weeping before the Lord. What the black boy had said he did not know; but he was bowed with wonder and filled with joy, for it was the power of the Holy Spirit.