A real Tanach prophecy about Xianity can be found in Isaiah 24:

Quote:
Isaiah 24:1 Behold HaShem empties the land and lays it waste, and He shall turn over its face and scatter its inhabitants. 2. And it shall be, as with the people, so with the priest, as with the slave, so with his master, as with the maidservant, so with her mistress, as with the buyer, so with the seller, as with the lender, so with the borrower, as with the creditor, so with the one who owes him. 3. The land shall be emptied and it shall be pillaged, for HaShem has spoken this thing. 4. The land has mourned, it has withered, the land has been humbled and withered, the highest of the people of the land have been humbled.


This indeed happened and Isaiah tells us that it happened because of Xianity:

Quote:
24:5 And the land has deceived because of its inhabitants, for they transgressed instructions, infracted statutes, broke the everlasting covenant. 6. Therefore, an oath has consumed the land, and the inhabitants thereof were wasted; ...


And everything that Sarah tells you, listen to her voice. Genesis, 21:12