The majority of humans seem to have a need for spirituality/religion built in. As has been often noted, when the common people lose their religion, they immediately start worshiping something else, like Dear Leader, The Party or Progressivism.
However, this creates a sort of "conflict of interest". The political authorities are vulnerable to corruption and error. They function best when they are treated as a necessary evil. Kept at arms length and watched like a hawk. Blind faith in the political authorities is dangerous. If the political authorities (Dear Leader or The Party) are your religion, you are hardly likely to treat them with the necessary skepticism.
Adopting an ideology like Progressivism as your religion is similarly problematic. Ideologies set out a blueprint for a certain desired social order. That is to say, they make claims about reality; do this and good stuff will happen. Claims about reality must be continuously and relentlessly tested to ensure that they are actually true statements about reality. Buying into an incorrect claim about reality is an easy way to fall into error. If an ideology is your religion, you are hardly likely to treat it with the necessary skepticism. You may even unconsciously ignore data that tends to falsify the your religion's claims about reality.
It seems to me that we were better off when religion was our religion. Making ideology into a religion has been disastrous.
The following quote applies to our times as well as it did to his revolution.
Over a half century ago, while I was still a child, I recall hearing a number of old people offer the following explanation for the great disasters that had befallen Russia: "Men have forgotten God; that's why all this has happened." Since then I have spend well-nigh 50 years working on the history of our revolution; in the process I have read hundreds of books, collected hundreds of personal testimonies, and have already contributed eight volumes of my own toward the effort of clearing away the rubble left by that upheaval. But if I were asked today to formulate as concisely as possible the main cause of the ruinous revolution that swallowed up some 60 million of our people, I could not put it more accurately than to repeat:
"Men have forgotten God; that's why all this has happened"