Jesus is the rock/stone/cornerstone
Here’s what it means
Jesus is the secure foundation, decisive chosen stone, and ruler on whom God’s people depend; rejecters stumble over Him.
Why the Bible says it this way
The writer uses a picture to explain one thing by describing it as another.
A helpful detail: Several stone texts are brought together in the New Testament. The shared image does not require every stone passage to have exactly the same emphasis.