Most people in the world seem to be materialists who deny-by-assumption the reality of the spiritual realm. By which I mean they assume the non-reality of entities such as God; spirits such as the Holy Ghost, angels and demons; the soul; and the possibility of life after biological death.
It is not that these have been sought and found to be absent - rather they are metaphysically-assumed to be absent, and therefore cannot be detected.
This is normal and mainstream. The materialist assumption is built-into the institutional discourse of all powerful social functions such as politics and government, the mass media, law, science, the arts, education, the military etc.
This is a post-religious world because once a person has adopted the materialist assumption; it is not refuted by any institution - not even by any church.
When the materialist looks for religion in 2021, he sees church organizations whose behaviour where it most matters (by materialist assumptions) is fully explained with materialist assumptions.
The churches themselves will state and behave on the basis that 'health', antiracism, equality, climate etc are more important than the spiritual - these take priority in their functioning.
If one is mainstream leftist; this means that where it most matters the churches are superfluous and offer nothing extra; but, if one is anti-left materialist; then it means that where it most matters the churches are wrong.
The mainstream materialist simply cannot perceive anything that the churches actually do which is at odds with what other kinds of institutions do.
In a nutshell; churches are institutions; institutions are part of The System; and The System is materialist by assumption; therefore churches are materialist by assumption.
This is a problem, unless you are already a Christian!
It means that, so long as people are already materialist yet seek to become Christians via a church - there is no compelling reason to become a Christian. Yes or no; it is merely a lifestyle choice.
This is why it has become so spiritually-damaging (so damning) that so many Christian churches insist that one can only be a real Christian within their church.
...When the actual situation seems to be the opposite: that one can only become a Christian outside the churches.
After one has become a Christian, then one can choose to join a specific church; if and when this is helpful to one's Christian life.
But one must first become a Christian; and as of 2021 that is a matter of each individual taking full responsibility for his ultimate personal destiny in this world.
If someone looks to any external authority or institution to tell him what to do - then he will merely remain in the materialist fly trap; he will merely continue to be-processed-by The System of Damnation.