These non-Christian elements being present (and it's debatable to what extent they were), in my opinion, is preferable to the non-Christian elements we have today (i.e. modernist globohomo culture). In fact, it's not even close.That's a very debatable statement to start with. Up until Late Medieval Times many non-Christian elements were present, even central to the faithful. Think folk magic, ancestor worship, the existence of fairees/elves/giants, the use of talismans, personal divination, the use of spells and incantations etc.
This is a very elitist view of Christianity (where only the well-educated, and not the "illiterate simpletons," can truly understand the faith). In fact, Christianity represents the opposite of elitism. You don't need an Ivy League education (or Medieval equivalent) or an IQ of 150 to be a true Christian.There were, and basically are, two types of Christianity. One for the (illiterate) masses, and the other one for the spiritual, theologically well versed clergy (who left all the written accounts). You can't expect an illiterate farmer to understand the intrisicalities of the Christian faith
I would argue that dependence on clerics (as opposed to everyone interpreting the Bible however they want) is very desirable and good.Illiteracy breeds dependance (on clerics), it breeds the spread (or resurgence) of pre-Christian beliefs and customs (due to theological illiteracy), and it creates a fertile ground for heresies (as many charismatic preachers cannot be countered due to the same theological blindness). If you can't read you also can't read the Bible
That doesn't mean it's bad to read the Bible. But even if you are able to read the Bible, you should still be trusting the interpretations of good priests and theologians, and not just interpreting it however you see fit.
The heresies and non-Christian beliefs we have today are worse than the ones in Medieval times, and, due to modern media and communication technology (TV, music, computers, etc.), these heresies and anti-Christian beliefs are able to influence people on a global scale and even become the norm, replacing Christianity (as opposed to merely influencing a few people in some remote village).