Peter and John had been arrested the evening before and now stood in the center of their accusers.  Who were those accusers?  The very ones who had accused Jesus in the last week of His life!  There was Annas the high priest and Caiaphas and others of high priestly descent.
  And interestingly, Peter used the same Scriptures that Jesus had used that last week of His life.  (Matthew 21:43-45)
(NASB) Psalm 118:22 “The stone which the builders rejected
Has become the chief corner stone.” 

  Notice how Peter used that quote against his accusers:
(NASB) Acts 4:11 “He is the STONE WHICH WAS REJECTED by you, THE BUILDERS, but WHICH BECAME THE CHIEF CORNER stone.” 

  The chief priests and other leaders had rejected the Lord Jesus Christ.  It was Jesus Who was the cornerstone to their faith and they rejected Him.
  It is the Lord Jesus Christ Who is the chief cornerstone of the Christian’s faith.   

  The Jewish “builders” had rejected the chief cornerstone of their faith in God.
  On what have you based your faith?  Have you based your faith on, and in, the Lord Jesus Christ as the corner stone of your faith?   

(NASB) Psalm 118:22-23 “The stone which the builders rejected
Has become the chief corner stone.
23 This is the Lord’s doing;
It is marvelous in our eyes.” 

  It is all of the Lord’s doing…it is His work, it is His word!  And is it marvelous from your viewpoint?
  Since it is marvelous for the followers of Christ, consider this:
(NASB) Psalm 118:24 “This is the day which the Lord has made;
Let us rejoice and be glad in it.” 

  Rejoice ~ followers of Christ ~ He is the chief cornerstone of your faith!