Perhaps I am missing something on your site, but what I have not seen is how the days after our Lord’s resurrection really changed the lives of the disciples. It seems to me that they were convicted up until the moment of the cross, but didn’t realize until the resurrection everything Jesus was here for. They seemed to waiver back and forth in their faith through out their time with Him, but as soon as they saw Him after the resurrection they absolutely believed, to the point of death.
The answer to your question is a simple one and is found in John 20:22. On the night of His resurrection Jesus breathed on the disciples and said, “Receive the Holy Spirit.” Luke 24:44-49 tells how He then opened their minds so they could understand the Scriptures. In 1 Cor. 2:14 Paul taught that the man without the Holy Spirit cannot understand the things that come from the Spirit of God. That’s what the disciples lacked before the resurrection, and that’s what caused such a remarkable change in them afterward.