1 Peter 2:7-8 Therefore, to you who believe, He is precious; but to those who are disobedient, “The stone which the builders rejected has become the chief cornerstone,” and “A stone of stumbling and a rock of offense.” They stumble, being disobedient to the word, to which they also were appointed.

You don’t hear much about cornerstones anymore.
It is the keystone to hold everything together, often rejected as too small.
I’ve done carpentry work, where there is always some scraps as you saw boards to length.
It never fails I end up using one of those small scrap pieces for something important.
That’s as near as I can get to understand a rejected rock that becomes the cornerstone.
Jesus is certainly rejected.
He was cast away. (crucified)
He returned. (resurrected)
Now He is seen as the cornerstone of the universe. (sitting at the right hand of God)
Salvation is through Jesus alone.
This edict is for all people but many stumble at the thought of a Jewish man as the Messiah/Savior.
And the rejection of Jesus continues.
All will stand before Christ for judgment.
Those rejecting this “chief cornerstone” are “stoned” by His words and cast into a lake of fire, which is the second death.
Basically, the oldest penalty of stoning becomes a reality for them.
Do not reject Jesus!