I don't want to be a Mrs Mangel Christian. If that doesn't make any sense to you, then you probably didn't grow up in the UK or Australia in the 80s and 90s, and I should probably explain. Nell Mangel was the semi-villainous old busybody in long-running Aussie soap opera Neighbours, back when the show had an inexplicably enormous following. She was, at least according to her own recurring phrase, 'a good Christian woman', and it was apparently her faith which drove her interfering, occasionally malevolent actions. She didn't like the young people enjoying themselves too much; she tutted and told tales as the older characters became romantically involved. Essentially, she saw every individual as a person to be judged against her own high moral code, and every situation as an opportunity to be judgmental – where possible even dishing out a sentence too. This, for her, was the bedrock of the Christian life.

In many ways, old Mrs Mangel was ahead of her time. Today, judging others has become a central part of entertainment, and of our everyday lives. Whether it's gossip magazines spreading rumours or splashing photos of a celebrity's sudden weight gain, or singers begging four judges to swivel their chairs on a TV talent show, we're accustomed to making deep, definitive judgements on the basis of very limited information. It's the basis on which prospective business stars lose their place on The Apprentice; it's the way many people have made world-changing decisions about their political leaders or their country's international future. Now we're all a bit like Mrs Mangel, making snap judgments and acting accordingly.

Perhaps the single biggest factor to impact this trend is the rise of social media. Now most of us spend time each day scrolling through our feeds, gaining tiny insights into the lives of people we half-recognise or barely know. She's had a baby, he's put on weight, they've split up, he's ranting again... we process these tiny snippets of information in nanoseconds and assign values to each person that they represent. Whether we realise it or not, social media streamlines the process of judging others, even making it socially acceptable.

Jesus addresses this behaviour on a couple of key occasions. 'Judge not, that you not be judged,' he says in Matthew 7:1 (a verse harmonised in Luke 6:37), before famously encouraging his followers to remove the plank in their own eye before picking at the speck of sawdust in someone else's. It's a good line that, but we shouldn't get distracted from the meaning: we judge other people chiefly because of our own insecurities; we attack others as a form of defensiveness about our own failings.

Then in John 8, Jesus has a moving encounter with a woman who is about to be stoned to death. Having been caught in the act of adultery, the Pharisees say that their law demands she now pay with her life. Jesus' response is legendary: he simply says: 'Let he who is without sin among you be the first to throw a stone at her' (verse 7). What happens next remarkable; instead of proceeding with her execution, the people start to slink away in realisation that as Paul later writes, 'all have sinned and fall short of the glory of God' (Romans 3:23). Here's the really interesting thing: in verse 9, John notes that as the people leave, it's the older ones who trudge away first. Not because they've been around longer and therefore accumulated more sin, but because their maturity has granted them a bit of wisdom into human nature. Jesus has turned their judgmentalism inside-out, and they're left reflecting on their own impoverished hearts.

All of this could leave us simply feeling introspective and a bit guilty, but I don't think that was Jesus' intention. Instead, I think he's just encouraging us not to be so hard on each other, because that's not our job. He's reminding us that he's the one who deals with sin, and that it's the role of God alone to judge.

Because of course, people are like icebergs. There's a lot more going on beneath the surface than we ever allow each other to see. When we see a guy we barely know posting a bit unwisely on social media about his mental health, we're unaware that he was bullied from the age of 11 to 18. When we hear about the couple who split up because of her affair, we're not party to the years of psychological abuse she suffered from her church leader husband. When a friend takes weeks to respond to a message, we assume they've been flakey when actually they've been sick. The judge-first, judge-quick culture infects the way we see the world, placing a filter of self-righteousness over our eyes that turns us into a distant relation of those first-century Pharisees.

In Galatians 6, as Paul encourages the church to act with Christ-like love, he implores them to 'test their own actions', instead of comparing themselves to one another. Then in verse 5, he seems to pick up that same theme that Jesus introduced: 'For each one should carry their own load.' As a thousand Insta-quotes are keen to point out, each person has a lot going on beneath the surface. Though our culture might train us to judge them anyway, a truly Christ-like response is so look past the presenting symptoms of dysfunction and see a person, just like us. They're carrying a load that's completely invisible, but might weigh a ton, and like us they're just trying to navigate the tough parts of life. Mrs Mangel had hit woefully wrong: the Christian response to sin isn't judgment, but Grace.

That mean old woman (I promise I'll update my cultural references soon) is important though. The fact is that the creators of Neighbours attributed her thin-lipped judgmentalism to her faith; and that's an association that culture has drawn over and again in the years since. Somehow, in spite of Jesus' rather clear words on the subject, his followers have become synonymous with moralising and calling out the behaviour of others. However that happened, it's up to today's church to dismantle that view. We're people who see the whole iceberg, and who, realising the depth of our own forgiveness, extend the love and mercy of Jesus to even our most dysfunctional Facebook friends.

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