Because God is our creator and Heavenly Father - he has placed us in this mortal life on earth with a good deal of inborn knowledge.
This knowledge - essential for our spiritual survival and salvation - is built-in.
In other words, a vital part of divine revelation - indeed the foundation of all divine revelation - is innate; and because we begin as babies, this knowledge is initially unconscious.
Therefore, Men have a natural set of assumptions - and these (for many human generations) formed the universal and inevitable basis of any chosen assumptions.
This situation was universal and inevitable, because unconscious.
As we grow older, some of this built-in revelation becomes conscious.
But there have been times in past ages where, it seems, not much of inbuilt revelation became conscious - the further back, the less conscious (it seems) Men were of this innate basis.
Much of divine revelation was therefore accepted passively, without any awareness; and therefore such knowledge was also built-into all the spiritualties and religions of the world, and it was the common property of all Men of ancient times.
(This is what CS Lewis called the tao, in his lecture series The Abolition of Man )
This innate, natural revelation was also a fundamental part of all traditional (pre-modern) forms of Christianity.
Other forms of revelation such as The Bible and the inner guidance of the Holy Ghost were built-upon this built-in revelation.
Thus, for instance, Scripture does not explicitly contain all that we need to know - because The Bible takes-for-granted a great deal of the common inheritance of all Men of 2000 years ago.
Scripture requires assumptions - but the necessary assumptions used to be very common, were unconscious; probably universal.
Therefore; Christian revelation (pretty much) 'just' adds-to (but in doing so, sometimes supersedes) the traditional revelations of the religions of the Ancient Hebrews, Greeks and and Romans.
(In different words: Christian Law is built-on Natural Law.)
It is sometimes said, for instance, that the Virtues are essentially common to all religions; except for Faith, Hope and Charity - which are the new and distinctively Christian virtues.
My point is that without our already built-in divine revelation; Christianity becomes not just arbitrary - but almost incomprehensible. Christianity becomes a house without foundations - which is exactly how mainstream modern Men regard it.
What has happened through the modern era is that Men have become increasingly conscious of innate revelations. These have come to general awareness and thus have ceased to be unconscious, spontaneous and natural.
The process of becoming conscious of our innate revelations was, of itself, an advance in human consciousness - it made us more grown-up in our divinity, and more free.
What God intended and hoped-for was that - having become aware of the nature of our built-in divine revelation - we would then consciously choose (from our new freedom to do so) to live in accordance with this foundational basis of all values.
But what instead happened was extremely different; and in accordance with Satanic and demonic intentions - rather than divine.
Modern Man became aware of one after another of the inbuilt revelations; but on observing that they were primary and not derived from this world; re-interpreted revelations as arbitrary and unjust prejudices.
And this has led to the rejection of more and more of innate divine revelation - its relabeling as unjust prejudice - and the attempted eradication of that which is built-into Men.
Instead there is the (stunningly successful) demonic project of the New Assumptions - which are intended to replace (now, supposedly discredited) built-in divine revelation.
Consider 'traditional' sexual knowledge, attitudes, values and morality. Over the past c250 years these have emerged into more and more general human consciousness. Men have become increasingly aware that they are assumptions - and in becoming aware have inevitably needed to make the choice of whether to accept them, or not.
Modern Men have become conscious of many details of their own sexual assumptions (mainstream modern culture points these out, repeatedly), and that these are innate assumptions - common to almost all Men.
But modern mainstream culture interprets these traditional assumptions as nasty, because they can be argued to lead to bad consequences.
In particular, traditional assumptions about sex/ sexuality often lead to reduced possibilities of short-term selfish pleasure. This meant that there was a ready audience for any attempt to discredit them - and a willingness to accept almost any rationalization that allowed individuals to think and do things that they wanted, but which went against innate revelation.
The (demonic) consequence is to regard (in principle) all that is an inbuilt, spontaneous, natural basis for our lives as being 'evil'; and we are in the midst of a vast (global) program to subvert, discredit and ultimately delete our built-in divine revelations.
The divinely built-in foundations of all knowledge are then - sometimes explicitly, sometimes implicitly in the process of being replaced by a new, modern, Leftist system of values that has zero foundation and no natural or spontaneous basis - indeed, quite the opposite!
The New Assumptions' unnaturalness and conflict with 'common sense' and common decency and whatever is universal and innate is regarded as evidence of their superiority!
The New Assumptions must therefore be imposed top-down by propaganda and coercion - as we see all around us.
The above analysis explains why we cannot 'reset' culture to the traditional assumptions based upon built-in divine revelations; because these are now conscious.
Because they are conscious, and because our consciousness shows them to be assumptions; the built-in knowledge with which God provided us must be chosen.
Never again can we live in spontaneous unconscious accord with innate divine revelations; never again can we regard the natural as necessary.
Instead, the path out from our current demonic system of imposed anti-divine assumptions is for us consciously to choose to base our lives, and our religion, on the inbuilt assumptions of divine revelation.
Christianity cannot be strong without foundations; and the foundations have been destroyed and replaced with evil, anti-divine, demonic assumptions.
It is our task (the task of each person reading this, for himself or herself) to rebuild the foundations provided by built-in divinely-revealed knowledge; through understanding what has happened, and then choosing to have God's revelations as our foundations.
And only on such a solid base - which we our-selves must participate in constructing - can future Christian Faith, Hope and Charity be built.
Only on such a base can Scriptural revelation again be effective, and the guidance of the Holy Ghost be known for what it is.