God Keeps His Word: Hebrews 6:13-18
“For when God made the promise to Abraham, since He could swear by no one greater, He swore by Himself, saying, “I will surely bless you and I will surely multiply you.” And so, having patiently waited, he obtained the promise. For men swear by one greater than themselves, and with them an oath given as confirmation is an end of every dispute. In the same way God, desiring even more to show to the heirs of the promise the unchangeableness of His purpose, interposed with an oath, so that by two unchangeable things in which it is impossible for God to lie, we who have taken refuge would have strong encouragement to take hold of the hope set before us.” Hebrews‬ ‭6:13-18‬
When God gives His Word, He keeps it. When He makes a promise, He follows through. God cannot lie. He can swear by nothing or no one greater than Himself. His character is faultless.

There are numerous texts in the Bible where God makes Himself 100% responsible for the outcome. For example, in Genesis 17:1-8 He made bold promises to Abraham about many descendants, a covenant and the promised land. Over time everything came to pass because God made it happen despite Abrahams lapse of faith.
Exodus 6:1-8 greatly expands on the same promises. This time God confirmed His oath to Moses. Again, He alone was responsible to fulfill these promises. He made these promises to Moses when the Exodus looked impossible. It is amazing reading. In the next 12 chapters, God did everything He promised while Israel stood by and watched. The entire Old Testament is the story of God keeping His Promises.
Interwoven throughout the Old Testament was the promise of the coming Messiah or Savior of mankind. (For example, see Isaiah 7:14-15 and Isaiah 9:6-7) Galatians 4:4-5 says that when the fulness of the time came, God sent forth His son, born of a woman, born under the Law, in order that He might redeem humanity. In His time, God always keeps His Word.
Jesus also made promises to His people. One of them is recorded in John 10:27-30. He promised that He would keep His sheep and that they would never perish. No one would be able to snatch them from His hand. The Father would also keep them. This text reminds us that God is ultimately responsible for the salvation of His people.
This whole text in Hebrews 6:16-18, bases the ultimate hope and assurance of our salvation on the unshakable promise and character of God. John 3:16-17 makes a promise of salvation to those who believe in Jesus Christ. Just like God delivered His people from Egypt under Moses, Jesus will save to the uttermost those who put faith in Him. The next two verses are even more profound.
Daily Bible Commentary By Terry Baxter: Cofounder of GoServ Global