You may have heard of the famous Monty Hall problem:
Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?
The answer is counterintuitive, but you actually have a better chance of winning by switching. The stick or switch scenario produces surprise and objection, with complaint from those who cannot see that switching increases one’s chances of winning (you can play here and see why switching is the best strategy). The main thing to understand about the Monty Hall problem is that it shows intuitive notions cannot always accept conditional probabilities very easily.
There are a lot of counterintuitive things about this world. We know from quantum mechanics and relativity that the very small and the very fast give us counterintuitive conditions that confound our expectations. We know that in the past a functional eye or a planetary system seemed too improbable to have evolved by nature's mathematical and physical laws. Furthermore, when one considers things like monotonic voting systems, 0.999 denoting a real number that can be shown to be 1, water being heavier in liquid form than in solid form due to the latter's reduction in density, or water vapour being lighter than air, our expectations seem confounded – particularly at a young age. The world is full of facts that confound our expectations.
We see the same thing in economics, when people frequently don’t understand at first glance why having safer cars causes more accidents, and why contraception actually increases unwanted pregnancies, and why stronger filtered cigarettes could lead to a higher incidence of lung cancer, and why lower percentage alcohol could result in more drunkenness, and why banning the transportation of animals for testing may well increase animal suffering, not reduce it.
I believe Christianity to be the world's most powerful and important truth, but it is quite a counterintuitive truth, which is a part of what St Paul is getting at when he says that no one can say "Jesus is Lord," except by the Holy Spirit (1 Corinthians 12:3).
When I was exploring the faith in my late teens and early twenties, I was struck by the apparent chicken and egg problem of belief: that one cannot know the truth of Christianity without a direct relationship with God through the Holy Spirit, but one doesn't have a direct relationship with God through the Holy Spirit except by knowing the truth of Christianity.
I would say that Christianity is the most counterintuitive truth with which we interface, not just because theology is the most complex subject in the world, but because the central essence of its grace is so outrageous and underserved that it can easily confound expectations, particularly for those who are primed to think of life in terms of a personal moral compass of meritocracy. Anyone who thinks morality is the be all and end all of human progress is going to find a faith based on a free gift of undeserved grace rather alien to the intuition.
By way of an analogy, Christianity is fairly similar to a riddle: that is, a riddle in prospect is often tricky, but in retrospect, once one understands how it is solved - it is obvious and transparent. Once one solves the riddle of Christianity and looks back in retrospect at their own journey of exploration (which can take weeks, months or years), one sees that part of the complexity was because consideration of the central essence of grace was absent from the riddle while it was still in prospect. Don't get me wrong, I am not comparing the Divine message to some sort of cryptic message He has set for us to solve – I use the term ‘riddle’ only with respect to how complex subjects seem at first obscure and counterintuitive, and clearer and more obvious once the logic trail induces clarity.
I contend that in Christianity we are being asked to consider something more counterintuitively profound than anything else the world has ever known - that of outrageous Divine grace. It appears to be contrary to every metric we value: we study hard, we get our rewards with good exam results; we work hard, we get paid and possibly promotion; we strive for moral probity, and we become a good person; we commit a crime, we go to prison - the list goes on. The commonality with these metrics is that the rewards outputted are roughly commensurate with the efforts inputted. Christianity radically departs from this worldly perspective, offering an outrageous offer of grace that makes perfect sense from the inside but beggars belief from the outside (I have personal experience of both perspectives).
To be a Christian you have to suspend all thoughts of getting better on your own merits, and accept a free gift of grace as a framework for becoming that better person. To fully live we have to die to self; to gain in abundance we must sacrifice; when we suffer we are to consider it 'pure joy'; and to lead a church congregation involves serving humbly bottom up not top down. No wonder it seems strange from the outside.
Forgiving our enemies is another aspect of grace where the world is often off kilter with Christianity. Humanity has a voracious appetite for justice and righting wrongs - yet when something amazing happens, like a mother forgives her son's killer, and victims of war torture become reconciled with their torturers through a grace-abundant reconciliation, we get a little sense of what it's like when God's goodness is working inside people, and why millions of highly intelligent and educated and worldly people have accepted Christ as Lord based on the fact that He did the same thing as Creator Himself on the cross.
Forgiving our enemies is another aspect of grace where the world is often off kilter with Christianity. Humanity has a voracious appetite for justice and righting wrongs - yet when something amazing happens, like a mother forgives her son's killer, and victims of war torture become reconciled with their torturers through a grace-abundant reconciliation, we get a little sense of what it's like when God's goodness is working inside people, and why millions of highly intelligent and educated and worldly people have accepted Christ as Lord based on the fact that He did the same thing as Creator Himself on the cross.
And there is perhaps no greater image of the continuativeness of Christianity than the Lord Jesus, Creator of the universe, washing the feet of His disciples. It's only when one accepts Him as Lord and Saviour that that action makes more sense. And that is probably because in discovering that our God came to serve, we uncover that other very counterintuitive thing about forgiving our enemies and those who have done us most harm.