"I can remember where I was the first time I heard this phrase. Our leader said, in one of those misty-eyed voices where someone looks up and gazes into the middle-distance: 'We must always have before us St Francis' most profound words: 'Preach the Gospel at all times, and use words where necessary'.

"We all nodded in the way that we do when we're convinced just by the reaction of other people that something very profound has just been said. Of course, there is absolutely no evidence that St Francis ever said it, and if he did, I would dare to suggest he's wrong.

"Is it not tantamount to saying: 'Feed the hungry, where necessary use food'?"

This was Chris Russell, the Archbishop of Canterbury's advisor for evangelism and witness, at a recent conference on evangelism hosted by Fulcrum. His frustration is that evangelism has been "relegated to the margins".

He set out what he called the "five containers of evangelism", which he said should "stretch and excite" all those who follow God.

1) Use words

"My understanding is that evangelism is a particularly Christian word. Inherent in it is the idea of something being proclaimed, announced and declared; something being set before people; it's something that we wouldn't know unless it was proclaimed to us," Russell said.

Physically telling others about the Good News is imperative for Christians, he argued. "Evangelism is the job of not keeping this to ourselves...God desires every person to live in the light of what he has done for them in Jesus Christ.

"Imagine the difference it would make to people if they knew what God has done for them in Christ – this is the task of evangelism."

Russell added that witnessing to non-Christians is not a "recruitment drive," but instead something we are compelled to do out of a committed faith and a love of God.

2) Don't make your witness formulaic

"We cannot just reduce these words to some formula, to some easily deliverable set of sentences...which could be the same for everybody, even though they're different people," Russell said.

"This message is about Jesus Christ, and he is always personable, always loving, always gracious and always particular. The Good News can't simply be some package that has to be delivered."

Jesus spoke to different people in different ways, and took into account the context of what he was saying. "Evangelism always needs to be in a particular dialect," he said.

3) Remember the Good News is for everyone

"No one is excluded from the work of Christ, and therefore this proclamation is for everyone...it matters that people know the love of God. It matters that everybody hears this," Russell said.

He explained that this means learning to live with "long-term disagreement", and walking alongside people on their journey towards faith, however long it takes.

"The commitment to evangelism is a commitment across all areas, including inter-faith...it isn't just about moving people on some kind of linear scale."

4) We are all witnesses, all the time

"Acts 1:8, Jesus' last words: 'You will be my witnesses when the Holy Spirit comes upon you.' It's not a verb, it's a noun. It's not describing how 'You will sometimes witness for me,' but it's who we are.

"Christians are those who witness of Jesus," Russell said. All Christians have something to share because they have a personal relationship with God – the only requirement of being a witness is having met the risen Jesus.

"Witnessing is simply that I tell and I live what has happened to me...witnessing and discipleship can't be separated, because Jesus can't be known apart from those who follow him."

5) Evangelism is costly

"There is no such thing as risk-free, easy proclamation or witness. Remember the word for witness is martyr, and the word martyr only came to have the connotations it has for us, because of the cost of being a faithful witness," Russell said.

"We're called to live lives that are absolutely unintelligible if Jesus Christ isn't alive," he concluded. "Discipleship, taking up our cross and following Jesus is the only way of adequately witnessing, and this is going to be costly.

"As St Francis of Assisi actually did say: 'It's no use walking anywhere to preach, unless our walking is our preach.'"