This document [2] is very good.

--- Notes

However, it makes no mention of religious studies.
As for the world’s three major religions—Christianity, Islam, and Buddhism—which continue to influence vast populations, we lack any substantive knowledge about them.
There is not a single research institution in the country led by Marxists, nor a single worthwhile publication on these subjects.
The journal Modern Buddhism is not headed by Marxists, and the quality of its articles is quite low.
Among other publications, works written from a historical-materialist perspective are also extremely rare; for example, the few articles on Buddhist thought published by Ren Jiyu [3] are already as rare as phoenix feathers and unicorn horns, while I have never seen any such writings on Christianity or Islam.
Without critically examining theology, it is impossible to write a sound history of philosophy, literature, or world history.
I ask our comrades in the Publicity Department to take this into consideration.
Mao Zedong, December 30.
Printed from the manuscript.
Notes [1] This is a marginal note written by Mao Zedong on a draft directive of the CPC Central Committee dated December 30, 1963, which forwarded a report from the Central Foreign Affairs Group and the Central Publicity Department on strengthening work related to the study of foreign countries.  [2] Refers to the report submitted to the Central Committee on December 15, 1963, by the Central Foreign Affairs Group and the Central Publicity Department, concerning the enhancement of research on foreign affairs.  [3] Ren Jiyu, born in 1916 in Pingyuan County, Shandong Province.
At that time, he was a professor at Peking University.