Thus God, determining to show more abundantly to the heirs of promise the immutability of His counsel, confirmed it by an oath, that by two immutable things, in which it is impossible for God to lie, we might have strong consolation, who have fled for refuge to lay hold of the hope set before us.
—Hebrews 6:17-18

Hebrews chapter 6 is known for its scare story about losing salvation. In fact this chapter contains a very great comfort from God, which we often do not notice or understand. There the Lord speaks of the so-called “two immutable things”, in which it is impossible for God to lie. What are these two things, and why did God need to confirm what He says with two things? Let’s turn to the Scriptures and see what this is about.

“For when God made a promise to Abraham, because He could swear by no one greater, He swore by Himself, saying, ‘Surely blessing I will bless you, and multiplying I will multiply you’” [Heb.6:13-14]. Here the author of Hebrews quotes Genesis 22:17, where God confirmed to Abraham what He had already promised earlier. So what are these two “immutable things”? The first is God’s promise: “Then He brought him [Abraham] outside and said, ‘Look now toward heaven, and count the stars if you are able to number them.’ And He said to him, ‘So shall your descendants be.’… Then He said to him, ‘I am the LORD, who brought you out of Ur of the Chaldeans, to give you this land to inherit it.’” [Gen.15:5,7].

Abraham doubted God’s promise: “Lord GOD, how shall I know that I will inherit it?” [Gen.15:8]. Doubt is actually sin [Rom.14:23]. But God did not rebuke Abraham, because Abraham was righteous not by works but by faith [Gen.15:6]. So what did God do? He made a covenant with Abraham: “So He said to him, ‘Bring Me a three-year-old heifer, a three-year-old female goat, a three-year-old ram, a turtledove, and a young pigeon…’” [Gen.15:9]. It is interesting to note that Abraham was a passive party to this covenant, because Abraham was asleep while God made the covenant, and a smoking oven and a burning torch passed between the animals. The smoke here is a type of the Father, because the Father always spoke from the cloud. And the burning flame is a type of the Son of God, because when Daniel’s friends were thrown into the furnace, there was a fourth man in the midst of the fire, like the Son of God [Dan.3:25]. If that is not enough for anyone, I will add that fire usually gives light, and Jesus said: “I am the light of the world”.

In other words, God the Father made a covenant with God the Son, each of whom must keep his part of the covenant, and Abraham in this case became the passive recipient of the benefits of the covenant. It is like a woman who marries a millionaire: he earned the money, and now she has every right to his wealth, without having earned anything herself.