Then he said to them, “These are my words that I spoke to you while I was still with you, that everything written about me in the Law of Moses and the Prophets and the Psalms must be fulfilled.” Then he opened their minds to understand the Scriptures, and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance and forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. (LUK 24:44-47 ESV)
Just as he did for the disciples on the road to Emmaus, he opened the eyes of the disciples in Jerusalem. And we find the key to them is seeing Christ suffer and rise from the dead. This gives meaning to all of Scripture.