Simply speaking, in religious reductionism, Christianity is reduced to a particular ideology, and something that can be intellectually understood to the exclusion of mystery. The most fundamental case is how God is understood, popularly as A) A kind of demiurge similar to the pagan gods with the only difference instead of having other Greek, Norse, Celtic, Egyptian, Mesopotamian, Indian, Chinese or Japanese gods, there is only the Jewish God. Like an invisible kind of sky father, or worse a dictator with an utterly human consciousness, only just happens to be bigger. On the other hand, there is the problem of depersonalizing God, into seeing him as a kind of an impersonal consciousness, the collective unconscious, everything in general and nothing in particular, or certain archaetypes like love, goodness, joy, peace, beauty, truth, or being.
Now both are essentially problematic. As the first is more of a barbaric superstition that makes Gods kingship no more than a kind of lucky chance of being the first being, and sole property owner of what he created, and therefore the only legitimate ruler. So it becomes a kind of arbitary setup where goodness is not essentially anything but who owns what, and how much power one has. On the other side of the Impersonal God is that it is impossible to relate to something that is less personal, who would appear to have the consciousness of a plant. But this falls into a kind of esotericism understood by a select few. I have nothing else interesting, as the impersonal consciousness is just that dull.
The Orthodox Church has made the distinction between how we can know God only through his energies or actions, but cannot grasp at his being, or essence. Which as I best understand it is that the intellect can only grasp at Gods actions, but will not understand Gods essence.
Then there are three other trends of reductionism that passes off as Christianity.
On the Legalistic, or Fundamentalist side, there is the trend to see law as the center of all reality, where arbitrary rules are the determining factor of what is good, with little concern for the people. Which is the tendency Anselmian Satisfaction that the law stated that for whatever reason, because Adam ate of an apple of the tree of knowledge, the law states that mankind must be damned eternally, unless an infinite man undergo the punishments of hell, that can only be effective if people learn about this man and have faith, and in other cases adds obeying a bunch of rules or avoiding certain vices before they die.
On the Humanistic, or Liberal side, man is the measure of all things, and all things are related to the pleasure of the mans egoic and earthly self. Where the main focus is on the rule of benovolence, pleasure, happiness, and relief from suffering. Where God is related to as nothing more than a kind of Cosmic butler only to be called on if you want something. Ultimately Gods favor is seen as an entitlement, and God is seen like a kind of Government that is for the people and by the people.
Both sides have major problems, for the first one cannot understand goodness without an authority creating rules and setting up harsh punishments. Which seems to be the root in why many feel so scandalized by Universal Salvation. The second side cannot understand a goodness that allows suffering, as it sees the happiness of the human as the ultimate end, and therefore allowing any suffering or severity is utterly scandalous.
Now the root of the misunderstanding is trying to understand the singleness and oneness of God, not as a kind of single truth to the exclusion of all other truth. But a fulfillment of all the partial truths. With the likes of CS Lewis, GK Chesterton, Peter Kreeft, and NT Wright, when truth is explained, all world philosophies are only incomplete shadows of the absolute truth of Christ. Where often times, Jesus is seen as one truth to the exclusion of all other truths, into a cultlike image. For example, the matter of heresy is not about trying to promote a certain ideology, and exclude another one, but heresy is whatever reduces Christ.
Often times, I have noticed that Jesus is made into a personality cult, where people claim different images of him to claim doctrinal or sectarian superiority. With the common phrase “Jesus said” or “the bible said”, which is typically some type of faulty literalism or taking some scripture out of context. Like the old myth that Jesus spoke more about hell than heaven, and the most about hell in the bible. Which is the primary justification used by infernalists for the doctrine. Which I understand quite well a projection of their own egoic image of Jesus. Even in the scriptures, people had a hard time understanding what Jesus was speaking of, even the disciples and the Apostles. And I cannot tell you how many images of Jesus we have, like the Hippie Jesus, communist Jesus, Right wing Jesus, homophobic Jesus, or Greedy Jesus. All being terribly far off.
There are also the matters of the constant fear of the devil, and seeing certain spiritual practices to be demonic or occult. Or on the other hand how many times, the experience of authentic life and experiences is often times suppressed if it does not match up to a certain set of theology. In these cases, I find that the problem is that all that is happening is that one is forced to suppress their own life experiences in favor for anothers understanding of truth, and can turn into occult when the practices are exulted above other practices. Which the real point scripturally speaking is that personal experience, mysticism, religious practices, scriptures, church, philosophy, and the like are only symbols of God, and therefore not to be suppressed, but neither idolozed. Which the common trend is to suppress one thing while idolizing another.