Luke 22-24

Even after Jesus had risen from the dead the disciples still couldn't understand what God had revealed of his plan of grace in the Hebrew scriptures. Finally, Jesus' words were able to penetrate the hearts of sin-broken men. In Luke 24:45 Jesus "opened their minds so that they could understand the scriptures." How did he do that? John recalled a miraculous imparting of the Holy Spirit on those believers (John 20:22). Maybe Jesus spoke with more clarity in his words. Perhaps they were able to understand because they moved from living by sight and began listening through faith (2 Corinthians 5:7). The last seems most likely to me since it is through our faith that we become receptive to the Gospel message.
Stuart