Most of the damage to mystical Christianity was already done by the time of the Nicene Council. This council set off a slew of others that systematically went about making war on all non-orthodox factions of the religion. Here, blind faith in a blind desert god was enshrined in dogma and establishing a tyrannical rule by priests became the overarching goal to which the Church’s resources and efforts were overwhelmingly directed.
However, if there is any one branch of Christianity to blame more than the others for the murder of mysticism and the systematic discreditation of all spiritual discipline in Christianity, the credit has to go to the Roman Catholic Church and the faithful “dogs” that it unleashed on the hapless peasants under its political and religious authority. All mystical or praxis-based approaches to spirituality had to go underground. We know of them now as the various secret societies whose hagiography is, to this day, shrouded in mystery, disinformation and wishful thinking. All we know for certain is that knowledge was passed on, piece-meal in many cases, and under the ever-roving eye of mainstream religious persecution.
On a conceptual level, centuries of Christian mystical atheism were kicked off by that scoundrel Thomas Aquinas and the Scholastic movement that he birthed.
Everything that Aquinas preached and, more importantly, his approach to religion, were revolutionary in nature. But what does the average modern mystical atheist, whether he be secular or Christian know about Aquinas? If they know anything, they have probably heard of Aquinas’ “proofs” for the existence of God. If they are of the faithful persuasion, they believe that these proofs actually hold up to scrutiny and that no one has been able to disprove them since. Sadly for them, in the years and centuries since Aquinas, his so-called proofs have been torn to shreds. This is because, while logically sound, all of them were predicated on assumptions and metaphysical givens that Aquinas took for granted. While they almost certainly were widely accepted in his time, consensus does not imply objective reality. The most famous proofs against his proofs came during the age of Enlightenment with philosophers like Hume and Hegel tearing them to shreds. Modern secular atheists, of whom Dawkins is probably the most well-known, also take great joy in tearing apart these proofs with ease to his gawking fans who clap along like trained seals thinking that Dawkins has disproven the existence of the immaterial when all he has really done is torn apart Catholic dogma.
I am not going to get into the weeds of the logic of these proofs in this post though. It would be pointless and counter-productive to the point that I am trying to make. The reason is that “logic” is the very problem at the heart of Aquinas’ entire approach to higher realities. Logic, put simply, is the wrong tool to use here. It is like trying to chop an oak tree down with a sword. An exercise in futility.