The pomp and circumstance of Christianity has always baffled me. It is misunderstood from the outside. It’s absurd that a religion could grow that fast, through such vast swaths of land. It got certain things right. This article, will try to touch upon it.
The study referred to (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214377) wasn't just about psychedelics but about any sort of experience of encountering God or "a higher power" or "ultimate reality" &c., but the statistic is (approximately) correct. According to the data in the Results section (Table 13), 21% of people who had such an experience while on psychedelic drugs were atheists before it, & 8% were after it; for those who had such an experience without drugs, the numbers are 3% & 1% respectively, & the numbers for each specific drug (Table 14) are similar. On the other hand, there may have been selection bias: advertisements for the study asked for people who had had "experiences of encounters with something that someone might call: God (e.g., the God of your understanding), Higher Power, Ultimate Reality, or an Aspect or Emissary of God (e.g., an angel)", & an atheist who had a subjective experience of this type but did not assign any cosmic significance to it may have been less likely to respond to the survey, so that the study may have had a larger percentage of atheists who converted after a religious experience, compared to atheists who didn't, than the general population.
The study referred to (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0214377) wasn't just about psychedelics but about any sort of experience of encountering God or "a higher power" or "ultimate reality" &c., but the statistic is (approximately) correct. According to the data in the Results section (Table 13), 21% of people who had such an experience while on psychedelic drugs were atheists before it, & 8% were after it; for those who had such an experience without drugs, the numbers are 3% & 1% respectively, & the numbers for each specific drug (Table 14) are similar. On the other hand, there may have been selection bias: advertisements for the study asked for people who had had "experiences of encounters with something that someone might call: God (e.g., the God of your understanding), Higher Power, Ultimate Reality, or an Aspect or Emissary of God (e.g., an angel)", & an atheist who had a subjective experience of this type but did not assign any cosmic significance to it may have been less likely to respond to the survey, so that the study may have had a larger percentage of atheists who converted after a religious experience, compared to atheists who didn't, than the general population.