Before the president of the United States can take office, he has to swear an oath. Historically, he puts his hand on a Bible, and he repeats these words from the US Constitution:
“I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States.”
Most presidents have added the words: “So help me God.”
But when God swears an oath, He doesn’t say “So help me…anyone else.” Why? Because God doesn’t need anyone’s help to stay true to Himself…
The letter of Hebrews is a sermon on encouragement (13:22). The author is wanting to encourage Christians to stay faithful to Jesus Christ, regardless of what the consequences might be in this physical life. To encourage Christians, the writer talks all about the blessings that are available in Jesus Christ.
In Hebrews 6, the writer states in verse 10 that “God is not unjust so as to forget your work and the love which you have shown toward His name, in having ministered and in still ministering to the saints.” So the writer wants Christians to know that God recognizes, remembers, and will reward our acts of service toward each other. Those acts might not get recognized in this life, but God will recognize them in the next life.
Because God remembers our acts of love and service, the writer states in verse 11 that we should show diligence in this area so that we can realize the “full assurance of hope” until the end of our lives on earth or until the end of the earth itself. We need to “imitate those who through faith and patience inherit the promises” (ver. 12).
One of those whose faith we need to imitate, he mentions in verse 13, is Abraham. God promised Abraham and God swore an oath to Abraham – recorded in Genesis 22:17 – that God would bless Abraham and multiply his family. Abraham waited; he waited; he waited – and eventually God fulfilled that promise to Abraham (ver. 15).
In verse 16, the writer wants to contrast the nature of God and the nature of human beings. Human beings, when they want to emphasize the importance of their word and the truthfulness of what they are saying, will swear by someone greater than themselves. Usually, men swear “by God.” Supposedly when someone says, “I swear by God,” then that should settle things because they are telling the truth, the whole truth, and nothing but the truth.
But what does God do when He wants to emphasize the truthfulness of what He is saying? Can He swear by someone higher than Himself? No. There is no one higher than God. Notice the words of the Hebrew writer in verse 17: “God desires to show to the heirs of promise [Abraham and his family and all those – including Christians – who will learn from Abraham’s life] the “unchangeableness of His purpose,” interposed – or guaranteed – with an oath.”
So, to show Abraham that God really, really meant what He was saying, the writer says God guaranteed it with an oath. But notice verse 18 – by two “unchangeable things:” God’s nature (that He cannot change; it is impossible for God to lie) and God’s oath – we can take strong encouragement from God and find refuge in God’s nature so that we can take hold of the hope that is set before us.
The word translated “unchangeable” here is also translated “immutable.” I wanted to introduce that word to you if you do not know the word. “Immutable” means “unchangeable.” Here, the writer is talking about God’s unchanging nature.
God is not One person one day and a different person the next day. He does not change. I, for one, have changed over the years. There are some bad things that I once did that I don’t do any more. There are some good things that I should have done my whole life but I started doing them when I learned better. You and I have changed.
God does not change. God does not need to change. And the Hebrew writer wants us to know that because God does not change, if He kept His promise to Abraham to bless him and his family and then fulfilled His promise, then God will fulfill His promise to us to bless us for serving each other in love, which is the context of this statement back in verse 10.
See these passages also: Numbers 23:19; 1 Samuel 15:29; Psalm 102:25-26; Hebrews 13:8; James 1:17.
Because Jesus is immutable, we can (and must) trust Him!
Paul Holland