We make evangelism scary in our heads. In a post-Christian culture, we worry we're going to come across as weirdos if we try to share our faith with our friends. As Christians in the average conversation about faith, we're probably carrying a lot more anxiety and baggage about the exchange than the person we're talking to. Which is strange, because our friends are generally interested in us – that's what makes them our friends.

Sometimes then, we even find ourselves in conversations with our friends where we're literally asked 'to give an answer to anyone who asks you to give the reason for the hope that you have', as Peter writes in 1 Peter 3:15. He's right to tell us to 'always be prepared' for these moments, but the truth is that often we're not. So here are seven thoughts on how to prepare for moments like this – be they at the school gate, in the pub or round the water-cooler (real or virtual). Use them to think about how you might share your faith the next time the subject comes up... and perhaps they'll even challenge you to start a few more conversations along these lines.

1. Less is more

One of the problems we can face with sharing our faith story is knowing which bits of the tale to tell. Especially if we've been Christians for a long time, there's so much we could say that we end up not knowing what to say at all. If someone asks you why you're a Christian, try to give one coherent answer, telling the story of how you came to faith, and the difference God makes in your life today. Tell them one story well – you probably haven't been invited to tell them everything!

2. Draw the contrast

If Christian faith doesn't mean you're different, either from the person you used to be or the non-religious people around you, then it probably isn't very persuasive. So when you tell others about your story of coming to faith, it's helpful to illustrate the point that you came from somewhere. If you've experienced a dramatic conversion from a hedonistic life of sin then this may be relatively easy, but for the rest of us, this simply means pointing out where your Christian faith makes you different. This shouldn't be an opportunity for piety, but may be a chance to say: I once was lost, but now I'm found.

3. Talk about a moment of realisation, even if there were several

You don't have to have a traditional Damascene conversion to be able to talk about the moments where the Christian faith started to make sense to you. All of us, even those who found faith in childhood can refer to times where faith suddenly seemed more real, and from a story-telling perspective these memories are really helpful as a way of explaining how normal people encounter God. It's really helpful for the listener when your story makes logical and chronological sense.

4. Reference a variety of reasons

I believe in God because I believe I've experienced and known his love personally. But that's not the only reason for my faith, and if it was I don't think that faith would be particularly resilient to challenge. I also believe because of the experiences and stories of trusted friends, the testimonies and writings of wise people through history, the ability the Bible has to both make sense of and speak prophetically into my everyday life... and for a host of other reasons. It's because of all of these factors that faith is compelling to me, and I also think it's understanding these many very different arguments that makes Christianity compelling to others. So when we talk about our faith, we should be careful not to present a one-dimensional case. There are many distinct and different reasons why we believe the Good News of Jesus is true.

5. Be honest about the challenges

God does not make your problems disappear, nor is following Jesus an easy road. Yet if we're not careful, we can try to insulate the watching world from these truths as if discovering them would make God instantly less palatable. In fact I think the reverse is true; our friends need to know that Christians are real people, with real problems and aspirations, who still make mistakes and suffer along with everyone else. You can't say 'Yes' to Christianity unless you believe it's something that a person like you could practise. So give your friends the warts-and-all version of your faith; they'll see your integrity, and they'll probably find the whole thing much more accessible.

6. Don't skip sin

It's important in evangelism to talk a lot about the grace and love of God, of course – in fact that should be our primary message to the world and to our friends. That being said, we must not lose sight of the fact that God's incredible love for us is most profoundly demonstrated in the fact that he sent his son as a rescuer (Romans 5:8). Jesus came – and died – to rescue us from something, and that is our own brokenness and 'sin'. I think one of the most common traits in modern evangelistic conversations is the editing-out of this part of the story, and that's a huge mistake which actually devalues God's whole offer to our friends. God redeems the very worst parts of our lives, and it's misguided to think that this idea wouldn't be attractive to hear about. Rather than projecting sin on to others or talking about it in an abstract sense though, personalise it; talk about your realisation of your own imperfection. Most people will find something to identify with in this.

7. Be confident – the Holy Spirit is with you

Finally, the most awesome piece of advice I've ever heard on evangelism came from the Christianity Explored pioneer Rico Tice, who said: 'Just remember that when you're talking to your non-Christian friend about Jesus, the Holy Spirit is also there whispering in his ear: "This is true, this is true, this is true."' Just remember that next time you have a conversation about faith, and may you rightly feel emboldened by it.

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