[Note: An oxymoron is a figure of speech that combines contradictory terms - such as painfully comfortable or gorgeously hideous.]
Can someone be a real Christian and an evolutionary scientist at one and the same time and without contradiction and without one eroding the other?
Many men of great spiritual authority would say no; and many of much shallower thinking say yes of course.
I am going to disagree with some of the deeper thinkers who would prohibit evolutionary thinking as un-Christian (but my disagreement is specific and dependent upon certain strict conditions); and also disagree with many shallower thinkers who see no problem at all in a Christian being any kind of evolutionist he might want to be.
Natural Selection has been and is a big problem for Christianity; but the essential problems arise from the fact that Natural Selection is science, and to the limitations of any science.
Of course, the problems and controversies of evolution come mostly in application to humans; so I will focus on humans.
Firstly, I think there is no significant problem about a Christian being scientifically or professional interested in evolution in the sense of adaptation within the human species
This is, indeed, pretty much common sense. Humans differ, many of these differences are heritable, and some of these heritable differences can be selected either artificially and purposefully, or by differences in the environment, to change human attributes.
In other words, human traits or potentialities can be amplified or suppressed by differential reproduction.
For example, resistance to some diseases is greater in some people than others, these differences may be heritable, and after several generations the outcome may be that a human population can become (on average) much more resistant to infectious diseases such as tuberculosis (e.g. in the case of Amerindians infected by Europeans), syphilis (e.g. in the case of Europeans infected by Amerindians) or P. falciparum malaria (in the case of many populations in Africa and the Mediterranian).
Humans can likewise by adaptation become (in principle) taller or shorter, stronger or slimmer, more or less intelligent, more or less impulsive, more or less dark or light skinned, retain the ability to digest milk into adult life and so on.
This kind of thing happens, indeed must happen - but of course in specific instances its effect may be weak, slow, or overwhelmed by other causes. So adaptation may, in practice, be real but unimportant, or presumed to be operating but invisible.
In other words, in the idea of adaptation by Natural Selection, children tend to resemble their parents more than random other people; and this family transmission can sometimes make a difference to the childrens' chance of themselves having children.
The tricky question comes in relation to the evolution of humans as a 'species'.
This is superficially the question of whether or how humans as a form evolved from non-human things (other forms of animals), and the assertion that this happened wholly by contingent and undirected natural selection acting on genetic (and other) variation.
What Natural Selection assumes is that the process of adaptation can continue, and did continue, to the point of leading to humans in all their essential qualities, without any form of divine intervention (and - logically - that the process is continuing and will continue).
Now, on the face of it, this cannot be acceptable to a Christian as a description of reality - but we need to focus upon what is it exactly that cannot be acceptable to a Christian.
What is absolutely unacceptable is to believe that the assumption of zero divine influence is the whole truth of the matter.
In the first place, it is not a discovered truth but instead a built-in assumption.
But if the built-in assumption is (for whatever reason) taken to be the discovered truth, then this would obviously be unacceptable to a Christian, because it directly contradicts Christian revelation in multiple ways, both fundamentally and superficially.
To accept the assumption of zero divine influence in relation to the essential nature of Man as if it were a fact, is indeed to replace Christianity with a mechanistic model that excludes even the possibility of meaning, purpose or any relationship between the individual and reality.
In the model of Natural Selection 'stuff happens' but it is not going anywhere nor for any reason nor nor does anything matter - it is a vision of existence as a process of permanent dynamic flux. Humans are just a passing phase of this flux.
(Indeed, since it is itself a human discovery, and since humans are merely temporary creatures, and human ideas merely a product of instincts created by Natural Selection; then any attempt to regard Natural Selection as a fundamental truth or primary reality is incoherent, self-refuting. If Natural Selection is true of everything, then human ideas do not reflect reality but are merely historical, contingent and open-endedly changing products of Natural Selection. Truth could only come from them by chance - and then they would not know it. How could a temporary eddy in the flux understand the flux?)
Why is it that so many people repeatedly mistake a built-in assumption for a discovered truth?
Because when so many people are playing the game of assuming that humans must have arisen from something else by pure Natural Selection sans God; everywhere you turn that is what people are doing: every new discovery from genetics, geology, anthropology or climatology is discovered on that assumption and fitted to the assumption; every mathematical model is built on the assumption. Every fossil fragment has been searched for on that basis and slotted into the current assumed lineage.
At no point is the assumption itself discovered, or tested; it remains necessarily untouched by all possible empirical findings.
Consequently, from within this evolutionary thought system, humans are conceptualized - from top to bottom - not only as having arisen by Natural Selection - but as the kind of thing that can arise by Natural Selection.
But the actual details of what happened and how it happened to get from non-humans to humans by pure Natural Selection change with bewildering speed - sometimes more than once a year: a single bone sometimes overturns the current fragile consensus.
This rapidity of change and lack of consensus means that this is emphatically not the kind of science which can be relied upon - and indeed it is not relied upon. The story of human evolution by Natural Selection merely functions as a story - more or less interesting according to taste.
It is essentially a matter therefore of popular science - and indeed it always has been. The professionals - whether fossil hunters or gene hunters or whatever - serve merely to generate material for popular science.
The current actual description of how Man arose by Natural Selection has been and is always contested, incomplete and self-contradictory, and above all labile - much more like the fluctuations of fashion than like something solidly useful.
Yet nothing about this lability disproves the assumptions of Natural Selection, nor does it have the slightest tendency to disprove the assumptions of Natural Selection; because nothing can disprove an assumption - not even in principle. That is the kind of thing an assumption is.
In a nutshell, natural selection is the understanding of humans that you get when you have assumed no divine influence.
But, there is - or certainly there can be - a way of doing evolutionary science in which the assumption of no divine intervention or influence in the 'origin of species' (including the human species) is made, but the fact that this was an assumption (and not a discovery nor a fact) is retained in consciousness.
The assumptions are made, and a game of following-out its assumptions, following its rules, is played.
This game of evolutionary science would have no more intrinsic validity than any other intellectual model - and in fact scientists do this kind of thing all the time.
Indeed, in a sense, that is just what science is - the business of making simplified working models (from which most things are left out) to try and deal with the incomprehensible complexity of raw reality.
So, scientists might predict the motion of a projectile assuming that the projectile has no volume, being a specific mass that occupies an infinitely small point, and in a simplified situation where there is gravity (which does not vary with height above the ground) and there is zero friction. The question is not whether this simplified model is true in the sense of real because we know it is not. But whether the prediction is accurate enough to be useful.
Indeed, this is the usual way science is done. The question is not whether the assumptions of science are true - because they are not true, and indeed are often changing very rapidly - but whether the answers obtained from the simplified assumptions are good enough for the purpose in hand.
So the validity of evolutionary science applied to the origin of the human species is intrinsically that of an intellectual game - and any real world truth or validity to this game is absolutely dependent upon testing the outcome in respect to the reason for doing the exercise.
We could say that the function of evolutionary science applied to the origin of human species is that of a 'Glass Bead Game'. An elite game (observed by the non-elite, but not played by them) in which the intrinsic intellectual fascination (i.e. the puzzle of constructing evolutionary lineages from partial, imprecise and constantly-changing evidence within the over-arching and strict rule of never introducing divine causes or reasons) is sufficient justification for its practice.
From this point of view, the elite intellectual game of constructing a human evolutionary lineage on the basis of zero divine influence, and purely caused by the selection of undirected variants seems to be, usually is, rather a functionless activity - it is not very clear what the purpose of it might be aside from the most obvious one of generating material for popular science: that is, for the highbrow entertainment industry.
Yet, it seems that historically one significant purpose of Natural Selection applies to the origin of the human species seems to have been (sometimes deliberately, sometimes implicitly) its application to replace and destroy Christianity.
Thus many or most prominent anti-Christians and atheists have been evolutionary scientists, right from the beginning of Natural Selection and continuing today.
It is hard to avoid the conclusion that this may me the underlying function of Natural Selection, and an indirect strategy to replace Christianity. Which would mean that Natural Selection must have a second assumption built into it: the assumption that what is in reality and necessarily a Glass Bead Game, is intrinsically a description of reality.
The covert but crucial assumption of Natural Selection as it is applied in scientific practice and popular science to the origin of the human species, may therefore be that it is not-an-assumption.
So, a Christian could legitimately engage in evolutionary thinking abut the origins of Man so long as he recognized the assumptions built into this game, and did not mistake these assumptions for discoveries, and did not attempt to make the outcomes or conclusions of this game into something with any necessary real-world functionality or relevance.
If, that is, he was content to play the game as a game; and not to pretend the game is other than a game.
To play the game of evolutionary science is intrinsically no more anti-Christian than to play a game of chess; unless you start to believe that chess is reality.
To believe that evolutionary theory disproves divinity is merely to observe that you don't need God to play chess, but then to infer from this factual observation that there is no God!
What happens within this game of evolutionary science has zero necessary relevance outside of the rules of that game - any applications to real life and the Human Condition are merely pragmatic (that is, a matter of usefulness for the task in hand), and each application must specifically be tested and proven - never assumed.
So a Christian Evolutionist could indeed exist, and need not be an oxymoron.