How does holy baptism signify and seal to you that the one sacrifice of Christ on the cross benefits you?

#HC69

In this way: Christ instituted this outward washing and with it gave the promise that, as surely as water washes away the dirt from the body, so certainly His blood and Spirit wash away the impurity of my soul, that is, all my sins.

Proofs

In this way: Christ instituted this outward washing (Matthew 28:19)
and with it gave the promise that, as surely as water washes away the dirt from the body, so certainly His blood and Spirit wash away the impurity of my soul, that is, all my sins. (Matthew 3:11; Mark 16:16; John 1:33; Acts 2:38; Romans 6:3–4; 1 Peter 3:21)