In constructing a stone building, a cornerstone is a main support element where two walls intersect. It was critical to select a quality stone because if the cornerstone would crack, break, or crumble, a major section of the structure would be at risk and likely fall.
As such, usage of the word cornerstone has come to reference anything that is indispensable or critical.
Therefore, it’s not surprising that the Bible calls Jesus a cornerstone (Ephesians 2:20). This is prophesied in Zechariah 10:4 and Isaiah 28:16, which Peter quotes in 1 Peter 2:6.
Other uses of cornerstone occur in Job 38:6 (referencing the creation of the earth), Isaiah 19:13 (prophecy about Egypt’s leaders), and Jeremiah 51:26 (prophecy about Babylonia).
Key verse about Cornerstone: The stone the builders rejected has become the cornerstone; (Psalm 118:22, NIV)
A lifelong student of the Bible, Peter DeHaan, PhD, wrote the 1,000-page website ABibleADay.com to encourage people to explore the Bible. His main blog and many books urge Christians to push past the status quo and reconsider how they practice their faith in every area of their lives.