Consider this. In many cases you must do one or multiple of these.

Convert a Satanist away from Satan.

Convert a cannibal away from cannibalism.

Convert a pedophile away from pedophilia.

Convince rogue CIA / Mossad they won't be killed by their handler for disobedience.

Convert an MKUltra away from their programming.

The Masons, Satanists and many MkUltra will not likely not be saved without extreme effort. Murderers, Pedophiles and Cannibals have even less of a chance.

You should also consider that many believe God to be evil and that they are hated by God. Many of these people will be unpersuaded.