Q72. Does this outward washing with water itself wash away sins?

The same division which we made when speaking of the sacraments in general, is also true of baptism, that there are some forms of speech which are proper, and others which are improper. These forms of speech are called sacramental. It is a proper form of speech when those who receive the sign are said to receive the thing signified, as "he that believeth, and is baptized, shall be saved." The same is true when the sign is said to signify the thing, as when it is said, "baptism is the sign of the washing away of sin." "He gave unto them circumcision to be a sign of the covenant." "Improper" or figurative forms of speech are when the sign is said to be the thing itself, as "Baptism is the washing of regeneration;" and when the sacrament is said to confer the thing, or things pertaining to that which is signified, as when baptism is said to save us. All these forms of speech may be said to have this one signification: Baptism is a certain sign of the remission of sin, and of everlasting life to them that believe: for the figurative speeches which are used in reference to the sacraments are to be interpreted in the same manner as the figurative speeches in reference to sacrifices. Sacrifices are often called expiations for sin, and yet the apostle Paul affirms that the blood of bulls, and of goats, cannot take away sin. So when it is said, "Baptism saves us," is "the washing of regeneration," and "the washing away of sin;" it is the same thing as to say, Baptism is the sign of all these things.