The early Christian churhc symbolized the Resurrection, healings, and miracles because the church thought those things were central. The reason the first and closest friends of Jesus focused on miracles, healings, and hopeful aspects of the faith such as the Ascension and Resurrection was simply that those are what God himself wants us to focus on. Those are the point. Those make Christianity such very good news. A dead man is not a great deal of help to us; a dead God is even worse.
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We say Christ died for us, and that is true. But Christ was also raised for us. His resurrection was as much for us as his death was.

-John Eldredge