Haggai 2:14

So is every work of their hands, and that which they offer there is unclean.

Works and pure hearts

They who have imbibed the true fear of God, do rightly serve Him though they may bring only a crumb of incense, and that others only profane the worship of God, though they bring many oxen; as a heathen poet says, “An impious right hand does not rightly worship the celestials.” The philosophers ever hold this principle--that no sacrifice is rightly offered to God except the mind be right and pure. But yet the philosophers, as well as the poets, adopted this false notion, by which Satan beguiled all men, that God is pacified by ceremonies: hence have proceeded so many expiations, in which foolish men trusted, and by which they thought that God would be propitious to them, though they obstinately continued daily to procure for themselves new punishments, and, as it were, avowedly to carry on war with God Himself. The prophet says that men not only lose all their labour, but also contract new pollution, when they seek to pacify God by their sacrifices, unaccompanied by inward purity. Works, however splendid they may appear before our eyes, are of no value or importance before God, except they flow from a pure heart. The fountain of works I consider to be integrity of heart, and the design and end is, when the object of men is to obey God, and to consecrate their life to Him. (John Calvin.)