It's the stuff of many a TV drama. A man collapses on a plane and the call goes out for a doctor. But this time the man who's collapsed is a Christian and the doctor who responds is a Muslim – and he accordingly refuses to treat the unfortunate patient.

This is how it goes.

'Dr Jaleel Kohmeni raised his hand when the flight attendant on Delta flight 6978 from New York to Las Vegas asked if there was a doctor on board. He told the attendant that he wasn't an American and that he preferred another doctor help if possible. Unfortunately, he was the man's only hope.

'As he approached, he could see that the man was barely managing to breathe and going in and out of consciousness. What the doctor did next may seem normal to people where he comes from, but here it was simply disgusting. He leaned over the man and asked him if he believed in God. "Yes," the man answered, "Jesus Christ is my Lord and Savior."

'At that point, Kohmeni informed the flight attendant that he could only "give the man the comfort of knowing Allah will give him the chance to redeem himself in heaven," but that he couldn't help save him.'

That's the story that was shared 24,000 times on Facebook. The trouble is that it didn't happen. It wasn't even fake news, or a hoax. It was posted on a satirical website, Daily World Update, which says in a disclaimer: 'Everything on this website is fiction. It is not a lie and it is not fake news because it is not real. If you believe that it is real, you should have your head examined.'

So, why all the likes and shares? It's possible that thousands of people got the joke and wanted to spread a bit of humour in a sad world.

The alternative is frightening, and more likely: most of them thought it was true. They've been conditioned, by an endless stream of hostile stories about Muslim hostility to Christians, to believe that that's really what a Muslim doctor would do.

And worse – if it's pointed out to them that they just didn't get the joke, they'd say, 'That doesn't mean it isn't true. It's just what they'd do, right?' So a light-hearted satirical piece has the unintended consequence of reinforcing the religious prejudice it was designed to expose.

Things like this happen when people's fear gets the better of their common sense and their humanity. How can a Christian combat this kind of thinking? Here are three suggestions.

1. Think twice, then think again, before you like and share something. Ask yourself: Am I really sure this is true? What's the evidence? Who's going to read this and what use are they going to make of it? There's a saying often attributed to Mark Twain: 'A lie can go around the world before the truth has got its boots on.' Christians should be lovers of truth. Psalm 141:3 says, 'Set a guard over my mouth, Lord; keep watch over the door of my lips.'

2. Only share what's loving and kind. There are stories out there that need to be told, about Christians who are persecuted for their faith. There are others that are designed not to elicit sympathy, but to stir up hatred. We should be deeply suspicious of anything that makes us think less of someone because of their religion, their race or anything else. We sin as individuals and we're judged as individuals. Proverbs 16:24 says, 'Gracious words are a honeycomb, sweet to the soul and healing to the bones.'

3. Think the best of people, not the worst. We are all sinners, but we are made in God's image. Continually focusing on what's wrong with people, majoring on their weaknesses, looking for conflict and stirring up hatred and fear, is bad for the soul. We can't make bad people good; but we can look for the good even in bad people. Yes, we're sinners, but we bear the traces of original goodness, left by the God who made us all. Malachi 2:10 says, 'Do we not all have one Father? Did not one God create us?'

Internet stories designed to spread hatred spread through thousands of individual channels. We may not be able to dam them all. But we can develop the kind of Christian character that means we, at least, won't be swept along with the tide of lies.

Follow Mark Woods on Twitter: @RevMarkWoods