"They went out and proclaimed that all should repent..." (Mark 6:12)

Imagine, just for a moment, that you are attending a church service, or watching a TV chat show – and a special guest is announced.

To your surprise, that individual is none other than Jesus. There he is! Envisage him walking up to the pulpit, or being welcomed on to the television programme by the host – undoubtedly to massive applause.

Wow! And now you're thinking: "Here we go! Jesus is going to do his stuff! It's going to be great!"

Except that it isn't... Jesus holds people spellbound to begin with – that's for sure. He certainly speaks with real authority. But, hang on a moment, what's that you hear from the back of the congregation or the TV studio audience? Surely it can't be... But it is! Someone is booing... And now there is a catcall... And now most of those present are joining in a slow handclap of disapproval.

What's going on? Well, the answer is that this is pretty much what we find in Mark 6 when Jesus visits his home town (v1) – and it is also what Jesus warns his followers to expect in some places as his message is proclaimed (v11).

When Jesus preaches at the place of worship in his home town, the congregation are initially astounded (v2) but their amazement quickly turns to disapproval – and then they take offence at him (v3).

And when Jesus commissions his friends to go out and preach further afield (v6-10), he warns them that there will be places where people "will not welcome you and... refuse to hear you" (v11).

What's the common thread running through this section? It's simply that some people will always take offence at the message Jesus brings. And although we're not told in detail by Mark precisely what Jesus preached at this point, we can be pretty confident the substance of the message was the same as that which he told his followers to proclaim (v12) and which he himself had focused on from the start (1:15): it's the message of repentance.

Repentance is a word that brings confusion to many. For non-Christians it too easily conjures up images of sandwich-board men proclaiming a message of imminent apocalypse. For others, perhaps, it is an archaic word with little or no meaning whatsoever.

But there's no doubt it's at the heart of Jesus' message. Repentance is more than feeling sorrow for particular things we've got wrong – it's a change of heart, mind and direction. It comes as we change how we view ourselves, God and Jesus. It comes as we decide to turn from an instinctively self-orientated way of living to a Jesus-centred life, with all the changes that this entails.

So let's remember two things:

(1) The gospel is always inclusive – but also transformative. Jesus' message is for everyone – period. But that message always includes the challenge of turning away from things he doesn't want and embracing the things that he does. Jesus told the woman caught in adultery that he didn't condemn her (John 8:11) – but added: "From now on do not sin again."

(2) The gospel demands ongoing repentance from all of us. Repentance is not a quick "sorry" prayer to Jesus at the start of our discipleship – but an ongoing part of our spiritual life. As Oswald Sanders wrote in his classic My Utmost for His Highest: "The foundation of Christianity is repentance... If you ever cease to understand the value of repentance, you allow yourself to remain in sin. Examine yourself to see if you have forgotten how to be truly repentant."

Is repentance the missing ingredient you need right now?

The Rough Guide to Discipleship is a fortnightly devotional series. David Baker is a former daily newspaper journalist now working as an Anglican minister in Sussex.