Indispensable Preparation (Acts 1:1-2)
Before presenting more history to Theophilus (meaning: dear to God) Luke speaks summarily about his previous writings. He tells his recipient that the former account is to be regarded as a comprehensive (πάντων) record of Jesus' works and words (Acts 1:1). Modern readers have come to know that prior work as The Gospel According to Luke. That record stops at the point when Jesus, having given his disciples a work for insight and a word of instruction, was taken up into heaven (Luke 24:51):
Opened he their mind (διηνοιξεν αὐτων τον νουν [diēnoixen autōn ton noun]). The same verb as that in verses 31 and 32 about the eyes and the Scriptures. Jesus had all these years been trying to open their minds that they might understand the Scriptures about the Messiah and now at last he makes one more effort in the light of the Cross and the Resurrection. They can now see better the will and way of God, but they will still need the power of the Holy Spirit before they will fully know the mind of Christ.
Robertson, A. T. (1933). Word Pictures in the New Testament (Lk 24:45). Nashville, TN: Broadman Press.
Witnesses are appointed by God and anointed for the work. Apart from both His election and enabling they cannot be effective.
Infallible Proof Examples (Acts 1:3)
What were the infallible proofs of Jesus' resurrection. There were many (John 20:30; 21:25). What follows is a sampling of what is recorded in the gospels and one provided by a former enemy of Jesus.
Displaying Scars from His Crucifixion (John 20:19-29) -
Displaying Signs from their Calling (John 21:1-23; Luke 5:1-8)
Disclosure to their Larger Company (1 Corinthians 15:5-7)