What does Isaiah 8:14 mean?
The Lord does not change (Malachi 3:6). He is holy and all-powerful. To those who honor Him as holy (Isaiah 8:13), the Lord is a place of refuge. Their hope for survival and abundant life rests in Him. In this way, God is like a large, stable rock: a secure foundation and place of safety (Psalm 18:2).However, to those who do not honor the Lord as holy, that same cornerstone becomes something a tripping hazard. God's truth cannot be denied, any more than a person can walk through a boulder. For those who reject Him, God becomes a "stumbling rock." He's something they cannot help but trip over. Everyone who tries to succeed and thrive apart from the Lord eventually falls and does not prosper. And for everyone who honors Him as holy, He is the solid rock on which they build their life.
Isaiah declares that it is the Lord who will become the stumbling stone for both houses of Israel. That means that both the northern ten tribes, Israel, and the southern two tribes, Judah, will be destroyed. The Lord will become a trap and a snare even to the people of Jerusalem in the end. They will refuse to honor Him, and that will bring them misery.
In the New Testament, Jesus describes Himself as the ultimate version of this rock (Matthew 21:42–44), the true cornerstone. Paul, too, makes clear that Jesus the Messiah is the stone of salvation for those who believe in Him (Romans 9:32–33).