One of the verses in the Glory Medley that we sing in our Fellowship is as follows:
“I lay in Zion for a foundation a stone
I lay in Zion for a foundation a stone
A tried stone, a precious cornerstone,
A sure foundation, a sure foundation.
A tried stone, a precious cornerstone,
He that believeth shall, shall not make haste.”
 
Isaiah 28:16,
“Therefore thus says the LORD God:
‘Behold, I lay in Zion a stone for a foundation,
  A tried stone, a precious cornerstone. a sure foundation’
  Whoever believes will not act hastily.’”
(Note:  Singing Scripture is a wonderful was of memorizing Scripture.)
 
“The Illustrated Dictionary of the Bible” Herbert Locktyer, Sr., Editor” defines cornerstone as: “a stone placed at the corner or the intersecting angle, where two walls of a building come together.  In biblical times, buildings were often make of cut, squared stone.  By uniting two intersecting walls, a cornerstone helped align the whole building and tie it together”
 
When Jesus came to the temple as recorded in Matthew 21 where the chief priests and the elders confronted Him as to His authority.  (Read 33-46 how Masterful Jesus is!)  
Jesus, in Vs,. 42;
“Jesus said to them, ‘Did you never read in the Scriptures: 
  ‘The stone which the builders rejected
   Has become the cornerstone.
   This was the LORD’S doing,
   And it is marvelous in our eyes’?”
He quoted to them Psalm 118:22
(You will find this also in Mark 12:10-11 and Luke 20:17
 
Peter quoted this same Psalm when he and John were before the rulers, elders and scribes as well as the high priest and members of the high priest’s family.  Acts 4:10-11 (Read verses 1-22 and clap for joy!)
“Let it be known to you all, and to all the people of Israel, that by the name of Jesus Christ of Nazareth, who you crucified, whom God raised from the dead, by Him this man stands here before you whole.  Vs 10
This is the ‘stone which was rejected by you builders, which has become the chief cornerstone.’  Vs. 11  
 
In Peter’s letter ‘to the pilgrims of the Dispersion in Pontus, Galatia, Cappadocia, Asia and Bithynia’, he writes 1 Peter, Chapter 2
verses 6-8,
“Therefore it is also contained in the Scripture,
   ‘Behold, I lay in Zion
    A chief cornerstone, elect, precious,
    And he who believes on Him will by no means be put to shame.’
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.’”
 
The stone of stumbling and the rock of offense has become the stepping stone for we, Believers!  The Lord Jesus Christ is our very life!
 
Jesus, the Cornerstone is the foundation of the church!
“Nor is there salvation in any other for there is no other name under heaven given among men by which we must be saved.”  Acts 4:12’
 
Ephesians 2:19-22 tells us both Jew and Gentiles are now one in Him,
“Now, therefore, you are no longer strangers and foreigners, but fellow citizens with the saints and members of the household of God, Vs.19
having been built on the foundation of the apostles and prophets, Jesus Christ Himself being the chief cornerstone,  Vs. 20
in whom the whole building, being joined together, grows into a holy temple in the Lord,
in whom you also are being built together for a habitation of God in the Spirit.”
 
The cornerstone, the foundation stone, gave strength to the two walls they connected.  And every other stone needed to be cut to the same pattern for the building to stand correct and firm.  Therefore, we as God’s chosen must conform to the pattern of Christ Jesus, The Cornerstone!
 
“For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren.  Moreover whom He predestined, these He also called; whom He called, these He also justified; and whom He justified, these He also glorified.”  Romans 8:29-30
 
All we can say is, “Thank you Most gracious, loving, glorious Lord God Almighty!”  Amen