WSC Q.92: What is a sacrament?
A sacrament is an holy ordinance instituted by Christ, wherein, by sensible signs, Christ, and the benefits of the new covenant, are represented, sealed, and applied to believers. (Gen. 17:7,10, Exod. 12, 1 Cor. 11:23,26)
WLC Q.162: What is a sacrament?
A sacrament is an holy ordinance instituted by Christ in his church, (Gen. 17:7,10, Exod. 12 (containing the institution of the passover), Matt. 28:19, Matt. 26:26–28) to signify, seal, and exhibit (Rom. 4:11, 1 Cor. 11:24–25) unto those that are within the covenant of grace, (Rom. 15:8, Exod. 12:48) the benefits of his mediation; (Acts 2:38, 1 Cor. 10:16) to strengthen and increase their faith, and all other graces; (Rom. 4:11, Gal. 3:27) to oblige them to obedience; (Rom. 6:3–4, 1 Cor. 10:21) to testify and cherish their love and communion one with another; (Eph. 4:2–5, 1 Cor. 12:13) and to distinguish them from those that are without. (Eph. 2:11–12, Gen. 34:14)
Sacraments are holy signs and seals of the covenant of grace, (Rom. 4:11, Gen. 17:7,10) immediately instituted by God, (Matt. 28:19, 1 Cor. 11:23) to represent Christ and His benefits; and to confirm our interest in Him: (1 Cor. 10:16, 1 Cor. 11:25–26, Gal. 3:27, Gal. 3:17) as also, to put a visible difference between those that belong unto the Church and the rest of the world; (Rom. 15:8, Exod. 12:48, Gen. 34:14) and solemnly to engage them to the service of God in Christ, according to His Word. (Rom. 6:3–4, 1 Cor. 10:16,21)