Westminster Larger Catechism
Q. 161. How do the sacraments become effectual means of salvation?
A. The sacraments become effectual means of salvation, not by any power in themselves, or any virtue derived from the piety or intention of him by whom they are administered, but only by the working of the Holy Ghost, and the blessing of Christ, by whom they are instituted[1047].
Westminster Shorter Catechism
Q. 91. How do the sacraments become effectual means of salvation?
A. The sacraments become effectual means of salvation, not from any virtue in them, or in him that doth administer them; but only by the blessing of Christ, and the working of his Spirit in them that by faith receive them.[188]
Daily Westminster 