A new user is asking countless questions which seem to have the goal of proving from Jewish texts that Mohammed was a real prophet. Do we just allow this to go on indefinitely? Personally, I have been enjoying MY a lot less the last few days with all these similar new questions constantly popping up on my screen.
Speaking generally, based on my past experience as a moderator:
When a user persists in behaviors that are contrary to community expectations, including promoting other religions, insulting Judaism, or fighting with other users, the moderators can exercise a special mod-only ability to communicate privately with the user (for the eyes of the user, the mods, and SE staff only) to ask the user to stop. If the user continues to persist in this behavior, the mods can suspend the account. If the user returns from suspension and continues with the objected-to behavior, the mods may suspend the account again or may delete it.
Flag as spam. The system will take care of it.