This is a well-established tactic by communists. They plant their operatives inside churches or other religious institutions. With some efforts, they could co-opt them, installing their puppets.
Though that’s not unique to Communists. Muslims for example used that tactic too, centuries ago, with Zoroastrians, and still do. It’s one reason Parsi Zoroastrians are still reticent to allow conversion or even permit non-Zoroastrians to enter Z temples - because some pretend with a sole purpose to infiltrate the community and gradually undermine it.