When I was 19 years old, I did the socially unthinkable. I changed my favourite football team. From the ages of 11 to 18, I supported Everton, and at 19, I switched my allegiance to West Ham United. Years of ribbing and ridiculing followed from my friends; I'm even aware that twenty years on, many football fans will read this information and immediately judge me. It's a strangely vulnerable thing to admit, even in these enlightened times.

There were mitigating circumstances of course. I'd only supported Everton in the first place because (a bit tragically) I wanted the most popular lad in my school class to like me and they were his team, and by my mid-teens that same lad was treating me pretty unpleasantly. I decided when I left school that I could be free of his influence, and so I ditched his football team too. I'd always had a soft spot for West Ham, so they were a natural shift into first position (not a phrase you usually see associated with them).

Even still, I knew I was seriously bucking a social norm. It's an attitude seen most prominently in social allegiance, but which also transfers to politics, social attitudes and religion. It's passed down along family lines, and reinforced by our social influences: you pick a side, and you stick to it.

We are most likely to vote, pray (or otherwise) and even support sports teams the way our parents did. And even if we decide at some point in our formative years to take an alternative or rebellious route in these areas, then we tend to become fairly entrenched in our views pretty quickly. We don't just set up camp on one side of a divide, we build a fortress there.

The advent of social media echo chambers has only helped to harden the walls. We tend to surround ourselves with people who think the same way as us (it's a good bet that around 75 per cent of your Facebook friends share your political and religious views) and so our own biases are constantly reinforced by a skewed reflection of the world. The angry and vitriolic nature of online debate has caused us to dig in to our positions even further, so when we do come up against someone with a different opinion to ours online, the result can be a battle instead of a conversation. We pick a side, stick to it, and fight anyone who disagrees with us.

This naturally leads to further polarisation. In politics, the centre ground that dominated the last two decades is rapidly disappearing, with a cast of characters emerging in the UK, US and elsewhere who are defined by their extreme political allegiances. Jeremy Corbyn, Donald Trump, Bernie Sanders, Marine Le Pen, Teresa May – none of them even try to occupy the central ground. They appeal to voters at one end of the spectrum or the other, and demand that the rest of us should pick a side.

This phenomenon is also visible within the church. It seems to me that there is an increasing shift towards theological polarisation, with the LGBT question, and sometimes Hell, being the trigger issues. Instead of genuine dialogue between a group of people on a journey of discovery, the conversation within the church these days is becoming a long-running argument about whether Jesus was a left-leaning hippy who loved everyone whatever their lifestyle and was only joking about hell, or an economically conservative moralist whose favourite topic was eternal conscious torment. There's almost no middle ground left.

In both politics and theology, that's a dangerous state of play, because when two sides are becoming more and more entrenched in their positions, and more certain of the foolishness of the other side, it's a recipe for war.

As this reality has emerged, that idea of switching allegiances has become more and more socially unacceptable. We're not used to changing our minds on things, and we know that there will be social embarrassment and other fallout if we do. We're conditioned to stick to our position and fight for it, rather than live with an open mind.

Closed-mindedness is the great silent character flaw that most of us are now living with a result of this cultural context. Not only are we conditioned to speak more than we listen, and to assume that conflicting opinions to our own are incorrect, but we're blissfully unaware of the fact. We don't address the problem, because we don't think we struggle with it.

The Bible contains quite a few people like this. Pharaoh, who wouldn't let the Israelites leave Egypt in spite of Moses' pleading and the devastation being wreaked on his land. The Pharisees, who were so obsessed with being right and keeping their religion, that they couldn't perceive their saviour standing right in front of them. Saul, who persecuted and slaughtered Christians in merciless observance of his own religious code, before God took dramatic intervention to redeem him. They all had hard hearts and closed minds, and not one of them recognised the fact.

For the sake of our future harmony, and for the sake of our own wholeness, we have got to get away from the unthinking extremes. The best kind of society, and the best kind of church, are those where everyone listens to and respects one another; where no-one is so certain of their own position that they can't be challenged or envisage ever changing their minds. It's fine to pick a side, and even to defend it, but it's time to become aware of how unteachable, how certain about everything we've become.

Paul writes, 'Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind' (Romans 12 v 2). Those words could not be more relevant at a time when society is demanding that we pick an extreme side and stick to it. Instead of consenting, and allowing ourselves to become utterly sure about everything we think, we should ask God to keep our hearts soft and our minds open; literally re-newed each day.

There are some practical steps we can all take to pursue this too. Engaging with voices outside of our usual bubbles, and listening for the things we can affirm, is a good one. Committing to listen more than we speak is another, as is being ready to back down and apologise when we realise we're wrong. Ultimately though, transformation only comes through seeking God's power to refine and reshape our character. God is much bigger than politics and theology, and while we seem determined to flock to the extremes of both, my hunch is that he's perfectly comfortable with his followers occupying the uncertain middle ground. Not being sure, or rather, the ability to change one's mind, is an act of humility instead of pride. So: when was the last time you put your hand up and said, 'I might be wrong'?

Martin Saunders is a Contributing Editor for Christian Today and the Deputy CEO of Youthscape. Follow him on Twitter @martinsaunders