Geerhardus Vos wrote much on the epistle to the Hebrews. In one particular essay published in The Princeton Theological Review (Jan. 1916), titled “Hebrews, the Epistle of the Diatheke” (Part 2), Vos makes an insightful observation about the nature of legalism that is worth pondering.
Legalism lacks the supreme sense of worship. It obeys but it does not adore. And no deeper notes of adoration have ever been struck than those inspired by the Reformed Faith, no finer fruit of the lips making confession to God’s name has ever been placed upon the Christian altar.