God’s Certain Promise

Hebrews 6:13-18

Oaths taken in ancient Israel were much different from oaths taken today. Oaths in ancient Israel’s day were not contractual as they are now. They were not sealed with a signature. Ancient Israelites sealed their oaths by their personal word. This is the nature of God’s oath with Abraham, which is the focus of this passage of Hebrews. God is an oath-giving God who seals his oaths with his own word and by his own name.

The context of verse 13 points to Genesis 22:16-17, where the Lord says to Abraham, “by myself I have sworn,” and also promises to greatly bless and multiply him. God swears by himself because there is no one greater to swear by. This, in fact, is why humans invoke the name of God when they take an oath in court or an oath of office. Abraham believed the promise because God was the promisor. By swearing by his own name, God guaranteed the fulfillment of his promise, so Abraham waited patiently and obtained what was promised. God swore by his own name to declare publicly for all creation that he was making this pledge to Abraham and that he would keep it.

The first “heirs” of God’s promise were Abraham and his descendants. In order to show the certainty and trustworthiness of his promise, God sealed his promise with an oath. But what does Abraham’s promise have to do with the author’s audience? For them, the heirs of the promise are those who have been adopted by faith in Christ as sons and daughters of God. As we have already seen in Hebrews 2:5-18, Jesus’s brothers and sisters share in Abraham’s promise.

The “two unchangeable things” the author mentions in verse 18 refer to the irrevocable nature of God’s purpose and word, and the oath that he declared publicly. Because it is impossible for God to lie, God never deviates from the truth in these two unchangeable things. God would cease to be God if he could lie.

The author reinforces God’s unchangeableness in order to encourage the church to once again hold firmly. The church is the refugee who must flee to God for rescue and who needs strong encouragement to seize the hope set before her. Because God’s Word is true and it is impossible for him to lie, we have all the confidence in the world to take heart and trust God’s promises just as Abraham did. The faithfulness of God and the certainty of his promises are not theoretical propositions. They are unchangeable realities. Like Abraham, we can stake our lives on God’s promises because God is the One who has promised them. Our God is a promise-keeping God.

Hebrews 6:19-20

The author poignantly reminds his people of their need for “an anchor for the soul.” The troubles and temptations of this world throw our souls around far too often. And yet, we have a sure and steadfast anchor that stabilizes our souls amidst the waves of this world. The promises of God are firm and secure enough to hold us steady in a storm. God’s promise and oath anchor the hope that “enters the inner sanctuary behind the curtain,” that is, the most holy place.

Once a year, on the Day of Atonement, the high priest went into the most holy place and offered the blood of an animal in order to turn God’s wrath away from Israel. Jesus, as our high priest, entered the inner place behind the curtain and offered his own blood on our behalf. Our anchor, Jesus, has gone before us as our forerunner to accomplish all that God’s justice required. As our great high priest, Jesus has purchased our salvation and assured us of the promises of God. Thus, Jesus’s atoning work on the cross predicates the Christian’s hope and anchors the Christian’s soul.