As I drove past, I barely noticed the broken down car on the grass verge at the side of the road. Except, something had caught my eye. ‘Wait a minute,’ I said to my wife, Alison. ‘Did you see the sticker on the back of that car?’

‘No, I don’t think so. Why? What did it say?’

‘I’m not sure,’ I replied. ‘But if it’s anything like what I think it was…’ I found the first safe place to U-turn, back we went and pulled up beside the abandoned car.

The very prominent sticker on the rear of the car was what I thought it was. In big bold letters it said: Got a problem? Just try Jesus!

I don’t have any issue with encouraging troubled people to turn to Jesus. It’s the right thing to do when you have problems, and even better to do it before you have problems.

But I do have issues with that way of communicating the message.

The least of my issues was that the sticker was a bad advert in those circumstances. That car looked like it had been broken down for several days. ‘Got a problem? Just try Jesus!’ clearly hadn’t got the car going. If I’d driven past it every day, I’d have been thinking, ‘What Jesus wants you to try now is calling a garage or a rescue service.’

However, I had more significant problems with that car sticker.

A 21^st century generation isn’t won over by trite messages. Sloganizing doesn’t impress. I’ve come across sayings like these:

• Why worry when you can pray
• Know God, Know Peace; No God, No Peace.
• Let Go and Let God
• When down in the mouth, remember Jonah. He came out alright.
• 1 Cross + 3 Nails = 4 Given

I almost like the Jonah saying, but it’s funny and understandable only for people who know their bibles. They, presumably, are not the target audience.

 Some slogans are much more troublesome than my examples.

An associate minister told me that, when he was younger, he used ‘conversation starters’ with university students.

‘What kind of conversation starters?’ I asked.

He listed them. I shuddered. The worst was probably ‘Turn or burn’. The rest were nearly as dreadful and offensive.

‘Who did you say them to?’ I hoped they were people he knew well and who wouldn’t be too upset. I was wrong.

‘I’d go up to students in a bus queue, tap them on the shoulder, and let them have it.’

It’s a wonder they didn’t let him have it. He thought his shoot-from-the-hip approach would get them talking. I suspect what most people said was ‘Go away,’ but with less polite language. When I asked him if he still used that technique sometimes, he said, ‘No, it didn’t work’.

Now there’s a surprise.

Some advertisers still sloganize, but many of the best prefer to tell a story or make people smile. They don’t smack them in the mouth with their message. They want people to think, and use subtlety and humour to achieve that. (Do an internet search for john lewis christmas adverts and you’ll see what I mean.)

In what most call the ‘western world’, there are two disturbing truths. One is that few people believe in God in a deep sense. The second is that many people have never even thought about God in a deep sense. We need to make people think, but slogans won’t do that. What’s easily said is easily dismissed. We can do better.

Slogans aren’t appropriate for serious business. And Christianity is serious business. One of the most important conversations of my life occurred when I was 17. I never expected it, and the way it happened was very odd.

My first year in journalism included study, and a few days of the journalism course were spent with other young reporters at a residential centre. The place was no upmarket conference suite; facilities were basic. I was allocated to share a room with John and Graham. I knew both of them already, including a strange peculiarity of John’s. He liked black. He liked everything around him to be black. His hair was jet black, and his clothes were all black (long before that was anyone else’s fashion choice). He told me how his parents had responded when he wanted black curtains, ‘John you’ve already got black wallpaper and now you want black curtains…?’He got his black curtains. John was a likeable one-off.

Late that evening each of us climbed into our narrow, dormitory-style beds, and John switched off the light. He also liked darkness. But the three of us talked, about lots of things and then one of them mentioned God. John was unmercifully direct: ‘So, what do each of you think about God?’ Graham mumbled something about reaching the age of ten and giving up believing God existed. Then it was my turn.

‘I believe in God…’ I said hesitantly. There was silence. They expected me to say more, but I didn’t have anything more to say. John and Graham had studied journalism with me for several months. They knew me. I’d never mentioned God before, and my lifestyle wasn’t bad but no advert for Christianity.

Then John’s voice came out of the darkness. ‘I respect you believing in God, but what I can’t respect is that you don’t then do anything about it.’

I remember nothing more of what was said that night. But John’s sentence stayed in my mind in bold capitals. ‘…WHAT I CAN’T RESPECT IS THAT YOU DON’T THEN DO ANYTHING ABOUT IT.’

When those words were still there next morning, and the one after that, I decided I had to talk to the minister of the church I (sometimes) attended.

But the minister went away to another church.

I went away for seven months to report the news in another city.

What never went away was that sentence spoken in the dark, by the unlikeliest of friends. How could I believe in God but do nothing in response to that?

After my seven month exile I returned, and found there was a new minister at the church. His name was Peter, and he seemed friendly. Almost my first sentence to him was, ‘I need to speak with you about God.’

One day every week after that I met with Peter, and  we talked about what lived-out faith meant. Gradually it made more sense. Late one Thursday night – really late – there was a moment when all my thoughts came together. I knew I had to say ‘yes’ or ‘no’ to God. If ‘yes’ my commitment would be everything. If ‘no’ I’d never go back to church. And, in the dark, at 2.40 that morning, my decision was made.

Next day, as soon as work was over, I phoned Peter and said I had to see him as soon as possible. ‘Come now, if you like,’ he replied.

Thirty minutes later I rang Peter’s door bell, was welcomed inside, and I told him what had happened early that morning, and that I’d said ‘yes’. I couldn’t have been more excited. Peter was too. We laughed, we prayed, and from that day on my life changed. A man called John had caused me to find a man called Peter – it sounds so biblical – and now I knew what believing in God had to mean: my life lived for him.

I’ve described that deeply personal story because it illustrates something very significant: Christianity is serious business. We can reject it or accept it. What we can’t do is be complacent or casual about it. We can’t tuck faith away in a corner of our minds, dust it off occasionally, but mostly do nothing about it. It’s far too important for that.

That’s why it’s wrong to tell people to just ‘try Jesus’.

A slogan saying ‘try Levis’ is fine because if you buy jeans and don’t like them you return them to the store or consign them to the ‘rarely used clothes’ shelf in the wardrobe. That’s okay, because jeans are a ‘take it or leave it’ commodity.

God is not a commodity. We can’t try God on for size, and if he doesn’t fit we’ll return him or ignore him. My strange friend John had helped me realise that you can’t really believe in God and do that. Believing in God must mean following God, and that’s a serious business.

A much more serious business than any bumper sticker can communicate.