The novelty of modern mainstream Leftism is that it is inverted in its values and incoherent in its ideology; this means that it cannot passively and unconsciously be absorbed; but instead those who follow it must do so by deliberate collusion with what they know to be evil.
A person growing up in the modern West may superficially seem merely to be engaged in the passive and unconscious absorption of whatever evil is propagated and imposed by The System of totalitarian evil as it is implemented through the mass media, schools and colleges, the legal system, the workplace etc. People might thus be assumed absolved from blame... But the process is in reality neither passive nor unconscious.
Every individual knows naturally and spontaneously that the mainstream values are wrong, therefore there must be a conscious choice to adopt evil - knowing its evil.
This is the case because mainstream Leftism is both un-natural and incoherent; and therefore each person has innate abilities to discern this evil simply by instinct and common sense. In other words, the inversions, untruths and incoherence of modern Leftist ideology are so stark that they require no education in order to know them.
For instance, the unbiological nature of the sexual revolution as it applies to sexual identity, sexual practice, positive valuations of behaviour etc, are (in increasingly many respects and in extremity) directly opposed to our innate biological instinctive knowledge. Thus modern sexual revolution is anti-survival, anti-reproduction, anti-child-rearing - and is instinctively known to be a path to extinction.
Therefore, Leftist sexual morality can only be adopted by a deliberate choice to invert our built-in, natural law and spontaneous evaluations. Thus, modern Leftists need to embrace childlessness, a declining and ageing population, and extinction as positive values. This cannot be a passive and unconscious process.
As another example, the grossly contradictory assertions relating to the mainstream Leftist themes of equality, feminism, antiracism is judged incoherent by the simple application of 'common sense' - that very basic and necessary use of reason and logic which all normally-developed adults posses in order to function even minimally.
To assert mutual contradictions is necessarily a choice, and therefore cannot be regarded as merely passive and unconscious absorption of values. Thus, incoherence needs positively to be adopted as an inversion of spontaneous morality (a new morality as inversion of common sense) - and indeed incoherence is increasingly a mandatory and coerced behaviour that must be cooperated-with, endorsed and celebrated.
So far, this has nothing to do with specifically Christian morality and values - I am simply talking about the basic, biological - often evolved - social equipment of Man; about 'natural' and spontaneous behaviours.
Where religion comes in, is in valuing that which is biological and common-sensical above that which is anti-biological and incoherent. That requires a divinity, outside of the social system.
In rejecting its native Christianity and not replacing it with any other religion; The West has made 'values' merely into 'whatever The System says'; and rendered itself helpless in face of the permanent revolution against biology and coherence that is modern Leftism.