11:45 be holy. The word “holy” means “separate” or “set apart.” Only God is intrinsically holy. He is by nature majestic, awesome, and pure. He demonstrated His transcendent holiness by His creation of the world (Gen. 1:1, 3 and notes), by His great acts in history such as redeeming His people from Egypt, and by His perfect laws. Israel’s holiness derived from her unique covenant relationship with the only true and living God. His covenant provided, among other things, moral and judicial laws that reflected God’s own righteous standards, and the sacrificial system to cleanse them from sin. The immediate background for this designation of Israel as a “holy nation” is the Lord’s appearance on Mount Sinai: they washed their clothes, avoided contact with the mountain, and abstained from sexual intercourse in preparation for that unique event (Ex. 19:10–15, 21–24; Heb. 12:18–21).
Jesus Christ, the Mediator of the new covenant (Heb. 8:6; 9:15; 12:24), also demands perfection (Matt. 5:48). But He provides the new Israel with holiness by His perfect sacrifice, which removed the sins of His people forever (Heb. 9; 10), and by His Holy Spirit, who inscribes God’s moral law on their hearts (2 Cor. 3:3; cf. Jer. 31:31–34). Without that holiness no one will see God (Heb. 12:14).