Did Resurrection Myth Precede Jesus?

Sheera Frenkel of The Times (of London) reports a debate of a Dead Sea tablet called Gabriel’s Vision of Revelation. She writes:

Israel Knohl, a biblical studies professor at the Hebrew University of Jerusalem, argued yesterday that line 80 of the text revealed Gabriel telling an historic Jewish rebel named Simon, who was killed by the Romans four years before the birth of Christ: "In three days you shall live, I, Gabriel, command you."

Professor Knohl contends that the tablet proves that messianic followers possessed the paradigm of their leader rising from the grave before Jesus was born. ...

Professor Knohl defended his theory at a conference at the Israel Museum in Jerusalem marking 60 years since the discovery of the Dead Sea Scrolls. He said that New Testament writers could have adapted a widely held messianic story in Judaism to Jesus and his followers.

Others, of course, dispute this interpretation of a damaged text.

I regard it as an intriguing but unproved theory.

But it won't affect modern Christianity, either way. If it were shown definitively that resurrection stories preceded Jesus, Christians would respond by saying that of course the resurrection was prophesied, and this is not diminished by its application to a false prophet.

It's not as though this is the only myth suspected to precede Christianity; other resurrection myths are known to precede it. For example, Paul Tobin summarizes:

The myth of Adonis was known to the Greeks as early as the fifth century BCE. The Egyptian myth of Osiris dates back to at least 4,000 BCE and was recorded in detail by the Greek biographer Plutarch (c46-120 CE). The Persian Sun-God Mithras was mentioned in the writings of the Greek historian Herodotus (c480-c245 BCE). The cult of Mithraism reached Rome in the first century BCE.

The way the early church fathers defended against the mystery religions showed that they knew these pagan myths antedated the Christian ones. Justin Martyr (c160-165) claimed that the devil plagiarized Christianity by anticipation with the pagan religions in order to lead people from the true faith. He claimed the myth of the virgin birth of Perseus, an ancient Greek legend that preceded Christianity, was pre-copied by the "deceiving serpent" (Dialogue with Trypho: 70). Similarly he asserted that the cultic rites of Mithraism had a diabolical origin (Apology 1:66). Tertulian (c160-c225) made the same claim: that it was the devil that provided this "mimicry" [notes omitted].

If you believe that there is a God who can raise people from the dead, that you will live forever in Heaven, that you talk to God, etc., then you'll hardly be troubled by conflicting resurrection stories. This is, after all, about faith. If we restrict the discussion to proof, then all resurrection stories are easily recognized as myths.