What does Matthew 24:35 mean?

The natural areas described by biblical phrases such as "the heavens and the earth" are the most permanent structures human beings can imagine. From our perspective, they seem unchanging and indestructible. They are not, of course. God created the heavens and the earth (Genesis 1:1), and God can end them.

Thus, for Jesus to say that His words are more unchanging, solid, trustworthy, and permanent than the heavens and the earth is one of His strongest claims yet to be an eternal being (John 8:58). Christ is declaring His ability to speak directly for the eternal God in heaven (John 8:38). Jesus was there when they began (John 1:1), and He will oversee their future state (Revelation 22:1–5).

After describing difficult-to-understand events of the future, Jesus is reassuring His followers that His words are absolutely reliable and cannot be thwarted in any way. We should never attempt to dismiss the words of Christ by saying, "yes, but that was back then…" What Jesus said would happen, did happen, and will happen (Revelation 19:11–15).