A definition of good and necessary consequence is already implicit in the first chapter of the Westminster Confession of Faith. Good and necessary consequence is distinguished from matters concerning God’s glory, man’s salvation, and faith or life that are “expressly set down in Scripture.” This includes direct precepts, prohibitions, statements of truth, and clearly approved examples. According to this statement, the term “good and necessary consequence” refers to doctrines and precepts that are truly contained in and intended by the divine Author of Scripture, yet are not found or stated on the surface of the text and must be legitimately inferred from one or more passages of Scripture. As the phrase indicates, such inferences must be “good,” or legitimately drawn from the text of Scripture. In addition, they must be “necessary,” as opposed to imposed or arbitrary.

RYAN M. MCGRAW, BY GOOD AND NECESSARY CONSEQUENCE, 11-12.