WSC Q.89: How is the Word made effectual to salvation?
The Spirit of God maketh the reading, but especially the preaching of the Word, an effectual means of convincing and converting sinners, and of building them up in holiness and comfort, through faith, unto salvation. (Neh. 8:8, 1 Cor. 14:24–25, Acts 26:18, Ps. 19:8, Acts 20:32, Rom. 15:4, 2 Tim. 3:15–17, Rom. 10:13–17, Rom. 1:16)
WLC Q.155: How is the word made effectual to salvation?
The Spirit of God maketh the reading, but especially the preaching of the word, an effectual means of enlightening, (Neh. 8:8, Acts 26:18, Ps. 19:8) convincing, and humbling sinners; (1 Cor. 14:24–25, 2 Chron. 34:18,19,26–28) of driving them out of themselves, and drawing them unto Christ; (Acts 2:37,41, Acts 8:27–30,35–38) of conforming them to his image, (2 Cor. 3:18) and subduing them to his will; (2 Cor. 10:4–6, Rom. 6:17) of strengthening them against temptations and corruptions; (Matt. 4:4,7,10, Eph. 6:16–17, Ps. 19:11, 1 Cor. 10:11) of building them up in grace, (Acts 20:32, 2 Tim. 3:15–17) and establishing their hearts in holiness and comfort through faith unto salvation. (Rom. 16:25, 1 Thess. 3:2,10–11,13, Rom. 15:4, Rom. 10:13–17, Rom. 1:16)