WLC Q.159: How is the word of God to be preached by those that are called thereunto?
They that are called to labour in the ministry of the word, are to preach sound doctrine, (Tit. 2:1,8) diligently, (Acts 18:25) in season and out of season; (2 Tim. 4:2) plainly, (1 Cor. 14:19) not in the enticing words of man’s wisdom, but in demonstration of the Spirit, and of power; (1 Cor. 2:4) faithfully, (Jer. 23:28, 1 Cor. 4:1–2) making known the whole counsel of God; (Acts 20:27) wisely, (Col. 1:28, 2 Tim. 2:15) applying themselves to the necessities and capacities of the hearers; (1 Cor. 3:2, Heb. 5:12–14, Luke 12:42) zealously, (Acts 18:25) and fervent love to God (2 Cor. 5:13–14, Phil. 1:15–17) and the souls of his people; (Col. 4:12, 2 Cor. 12:15) sincerely, (2 Cor. 2:17, 2 Cor. 4:2) aiming at his glory, (1 Thess. 2:4–6, John 7:18) and their conversion, (1 Cor. 9:19–22) edification, (2 Cor. 12:19, Eph. 4:12) and salvation. (1 Tim. 4:16, Acts 26:16–18)