Psalms 118:22-23 NLT
[22] The stone that the builders rejected has now become the cornerstone. [23] This is the Lord’s doing, and it is wonderful to see.
https://bible.com/bible/116/psa.118.22-23.NLT
Matthew 21:42-44 NLT
[42] Then Jesus asked them, “Didn’t you ever read this in the Scriptures? ‘The stone that the builders rejected has now become the cornerstone. This is the Lord’s doing, and it is wonderful to see.’ [43] I tell you, the Kingdom of God will be taken away from you and given to a nation that will produce the proper fruit. [44] Anyone who stumbles over that stone will be broken to pieces, and it will crush anyone it falls on.”
https://bible.com/bible/116/mat.21.42-44.NLT
Cornerstone definition;
1. The first stone that is set in a foundation, upon which the rest of the foundation is built.
2. The most important or fundamental piece on which something is built.
Christ is not only the cornerstone or head of the Church. He is the Chief cornerstone upon which the church is built. He is the foundation upon which our house is built, both individually as followers and believers, and collectively as the body of Christ. He is the head. We the Church members are the body, each having a function. Just as every physical body has many parts, each with an intended purpose, so the body of Christ being many members has a specific purpose for everyone in the church.
The stone which the builders rejected; the psalmist is referring to Israel who has rejected Messiah. This is what Jesus meant when he said in the Gospels, “the Stone which the builders rejected has become the Chief Cornerstone. Jesus was not referring to the temple that the Israelites built with their hands, but to Himself, who is the Messiah, whom Israel had rejected, except for a small percentage who did receive him as Messiah, as spoken through the Prophets.
When Jesus claimed to be the Chief Cornerstone whom the builders (Israel) rejected, he was saying that the foundation of the Kingdom of God is built on Him, as the Messiah, first born of creation.
If we reject Christ as Lord and Savior, we’re rejecting the Chief Cornerstone of salvation. Anything we build without Jesus Christ as the cornerstone, will be built on sinking sand. Those who build on Christ are building on a solid foundation. Jesus is the Rock and the Chief Cornerstone. A house built upon the words and teachings of Christ will stand in the mightiest of tempests and storms.
Matthew 7:24-25 NLT
[24] “Anyone who listens to my teaching and follows it is wise, like a person who builds a house on solid rock. [25] Though the rain comes in torrents and the floodwaters rise and the winds beat against that house, it won’t collapse because it is built on bedrock.
https://bible.com/bible/116/mat.7.24-25.NLT
Jesus Christ is not only the cornerstone of our lives, but of the Church, which is His body collectively. Each one of us is like a brick in the wall of a church or temple. We bring the Kingdom of God with us as we gather. Together we exist as one body, one church. We are many “bricks” but he is the one who holds us together. He is the foundation upon which the church is built, and the gates of hell will not prevail against her.
1 Corinthians 3:10-15 NLT
[10] Because of God’s grace to me, I have laid the foundation like an expert builder. Now others are building on it. But whoever is building on this foundation must be very careful. [11] For no one can lay any foundation other than the one we already have—Jesus Christ. [12] Anyone who builds on that foundation may use a variety of materials—gold, silver, jewels, wood, hay, or straw. [13] But on the judgment day, fire will reveal what kind of work each builder has done. The fire will show if a person’s work has any value. [14] If the work survives, that builder will receive a reward. [15] But if the work is burned up, the builder will suffer great loss. The builder will be saved, but like someone barely escaping through a wall of flames.
https://bible.com/bible/116/1co.3.10-15.NLT