If we ask any astronomer, they will tell us astrology is untrue.
And if we ask any Israeli archaeologist, they will tell us the Exodus didn't occur.
But astrology is the foundation stone of most religions, and the Exodus is the a founding story of the Bible. But both are untrue.
In other words, when we believe in astrology or the Bible, we are believing something which is untrue.
This is massive cognitive dissonance which is met with dissociation and denial followed by shooting the messenger.
The dissociation, denial and shooting the messenger are understandable for cognitive dissonance is emotionally painful and naturally we instinctively avoid pain.
And in particular when we don't understand why the pain is occurring, we naturally avoid it.
But once the cat is out of the bag. When all astronomers and all Israeli archaeologists tell us our beliefs are false, the pain is inevitable. And it is the pain of loss - the loss of our beliefs. And no matter what we do, the cat won't get back in the bag.
So to become whole again, to become wholesome, we need to mourn. We need to mourn the loss of our beliefs. And our only consolation is that we can mourn together.