Westminster Shorter Catechism

Q. 89. How is the Word made effectual to salvation?

A. 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.

Q. 90. How is the Word to be read and heard, that it may become effectual to salvation?

A. That the Word may become effectual to salvation, we must attend thereunto with diligence, preparation, and prayer; receive it with faith and love, lay it up in our hearts, and practice it in our lives.