Why did the Jews lie about Jesus?

[fredd bear]

If one drops ideas of biblical inspiration and the like in favour of mining historical data, one can go a little bit beyond mere hair splitting.

The Early Church didn't invent the story from nothing; if you're trying to persuade folk that something very strange has happened, you don't bundle it up with a ready-to-serve alternative explanation. The Xians wouldn't want to put the idea in people's heads that they had stolen the body, unless they had little option but to discuss it.

It seems far more likely that the Jews of Matthew's day actually were using the story as a counter-apologetic. The Xians were making a claim about Jesus' body, and the Jews were providing an easy alternative explanation. Justin (Dial. 108) reports that the story was still being used by Jews against Xians in the mid second century.

One thing that emerges from all this is that whatever the origin of it, the Early Church's claim was all about a physical body vanishing.

You might be correct. It's more likely that they stole/borrowed the resurrection story from other religious tall tales.

 The dying and reborn god is a neolithic idea.  Common in fertility cults; IE the death of winter and the reborn spring.

More closely pre Christian is the Isis and Osiris myth.

Christianity had no new ideas.  Some was traditional Judaism, some possibly  lifted  from the mystery religions .EG"Turn the other cheek" was certainly at odds with Mosaic law, with its emphasis on compensation, but hardly original. The Buddha had gone even further 600 years earlier with the concept of  'ahimsa'

It is often hard to work out the origins of beliefs/customs/ideas.  Correlation does not prove causation. The simplest explanation is that people commonly have similar ideas at the same time, in different parts of the world. That seems to have occurred with some major inventions of the 20th century .