Holiness and purity.

Herman Witsius has written:

“Holiness denotes that purity of a man, in his nature, inclinations and actions, which consists in an imitation and expression of the divine purity or holiness. God is the great pattern of his rational creatures. His will is expressed in the law, which was the pattern shewn to Moses in the mount, according to which the sanctuary of our soul ought to be framed. But his divine virtues or perfections are a pattern, which we are to contemplate with so much diligence, attention, and devotion, as to be ourselves transformed according to that, 1 Pet. i. 16, 17. “But as he which hath called you is holy, so be ye holy in all manner of conversation: because it is written, Be ye holy, for I am holy.” Virtue or holiness may be considered in different respects. As it agrees with the prescription of the law, it is call righteousness; but as it is conformity to God, and an expression of his purity, it is termed holiness.”

(Witsius, Herman. The Economy of the Covenants Between God and Man, Volume II, Kingsburg, CA: den Dulk Christian Foundation, 1990, p. 5-6)