I've been brooding on a few paragraphs Rudolf Steiner wrote - not for the first time; but they came to mind - seem relevant.
(See excerpt below.)
A large proportion of people nowadays, far more than in Steiner's time; are de facto atheist - either explicitly or implicitly. And this means they are ill - mentally ill, superficially, but with a subtle physical-biological cause.
Even in a strictly biological evolutionary context; humans are made to believe in deities. And when they don't, when they deny the gods; they cannot function - become incoherent (lacking any centre and focus for their instincts and learning) and all-but cease to reproduce.
Atheist Man also ceases to be able to learn from experience - because his experience breaks down into disconnected, arbitrary, incomprehensible pieces.
Living in an arbitrary world; the God-denier lacks even the basic instincts for survival - he feels no reason why he, people like himself, his family, his groups - why any of this has any reason to continue; he indeed typically harbours hatred and resentment against whatever is like himself - a desire of suicide, extinction, to be replaced; he regards death as annihilation, and hope that it will put an end to all consciousness.
Yes - this is already a world of sickness and death.
Edited from How do I find the Christ? A lecture by Rudolf Steiner (1918)
In the first place there is in man an inclination, a proclivity, to know what may be called in a general sense, the Divine.
The second inclination in him — that is, in the man of today — is to know the Christ.
The third inclination in man is to know what is usually called the Spirit or also the Holy Spirit.
There are men who deny all these inclinations. In the course of the nineteenth century, in European culture at any rate, men have denied the existence of anything Divine in the world.
What is it that makes a man deny the existence of the Divine — the Father God in the Trinity? In every such case there is an actual physical defect, a physical sickness, a physical flaw in the body. To be an atheist means to the spiritual scientist to be sick in some respect.
It is not, of course, a sickness which doctors cure — indeed they themselves very often suffer from it — neither is it recognised by modern medicine. There is an actual sickness in a man who denies what he should be able to feel, in this case, not through his soul-nature but through his actual bodily constitution. If he denies that which gives him a healthy bodily feeling, namely that the world is pervaded by Divinity, then, according to Spiritual Science, he is a sick man, sick in body.
There are also many who deny the Christ. The denial of the Christ as something that is essentially a matter of destiny and concerns man's soul-life. To deny God is a sickness; to deny the Christ is a calamity. To have no relationship with Christ is a calamity.
To deny the Spirit, the Holy Spirit, signifies dullness, obtuseness, of a man's own spirit.
Atheism — denial of the Divine — denotes an actual pathological defect. Failure to find in life that link with the world which enables us to recognise the Christ, is a calamity for the soul. To be unable to find the Spirit in one's own inmost being denotes obtuseness, a kind of spiritual mental deficiency, though in a subtle and unacknowledged form.