[maryz]

You’ll have to be more specific, any references/sources would be helpful.

The Golden Bough is by far the most famous source. IIRC, there's some in Jessie Weston's From Ritual to Romance. Among the "dying gods," Baldr, Osiris, Dionysius and Adonis spring to mind. If you have access to C.S. Lewis's God in the Dock, the essay "Myth Became Fact" goes into the issue.

[count-your-change]

But were not these “dying gods” either fertility gods (crops and human) or sun worship gods like the Sol Invicta?

What do these have to do with Christianity and Newman's “Essay”?