Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ. -- Acts 2:36 (KJV)
In Matthew 16, once Peter had confessed Him, Jesus charged His disciples "that they should tell no man that he was Jesus the Christ." At Pentecost, Peter stands up in Jerusalem and tells all the house of Israel to know it assuredly.
Therefore
Peter's "therefore" points back to what God has done. Jesus was "delivered by the determinate counsel and foreknowledge of God," and the men of Israel crucified Him "by wicked hands." God raised Him up, "because it was not possible that he should be holden of it." Peter and the eleven are witnesses. Jesus, "by the right hand of God exalted," has shed forth what the crowd can "now see and hear." That morning they had heard Galilaeans speak "the wonderful works of God" in their own tongues.
Men had given their verdict on Jesus at the cross. God overturned it. Peter's certainty rests on that act of God, and it holds whether anyone agrees or not.
That Same Jesus
"That same Jesus" is the man they crucified, the one Peter confessed as the Christ. God has made Him both Lord and Christ.
The people who heard it "were pricked in their heart" and asked, "Men and brethren, what shall we do?" Peter answered, "Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost." They were to be baptized in the name of that same Jesus.
Some mornings your confidence runs low. A prayer seems to go unanswered, or you cannot feel what you felt a year ago. Peter's "know assuredly" rests on God's acts and on men who saw them. What God did in raising Jesus has not moved.
Read Peter's sermon again today, Acts 2:22–36, and rest your confidence where he rested his.
