Bismillah: Assalamo Alikum.
Please provide some authentic sources. There is no true Muslim website would ever say that "Islam did not rise except through Ali's sword and Khadija's wealth," that is absolute lie. This is yet another Anti Islamic website hiding under the name of Islam. (Like Ex Muslims forums which do not have a single Ex Muslim member). Or maybe it’s a Shi’a website which I do not believe in their sources at all.
Have you got anything else to prove that Khadijah was a Christian?
Salam
ammuslim