I had to smile when chatting to my nine-year-old grandson the other day. I asked him to explain his passion for rugby, and as quick as a flash he replied, "It's because I'm Welsh of course." It did my heart good to hear that, although I have to confess he is equally proud of his Japanese heritage.

St David's Day has come and gone, and it was good. But I for one found it helpful to celebrate our common heritage as a nation once again. I reckon we have a lot to learn from our patron saint's life too. The facts are few and far between of course, and much of what we do know seems to be the stuff of legend.

It is said for example that on one occasion, when he was preaching to a large crowd, the ground rose up, allowing everyone to have a better chance of hearing what he had to say. Now that's pushing things a bit too far and I find it pretty hard to accept, even as a proud Welshman who knows that God is still in the miracle business.

I'm not interested in the fanciful legends that surround our patron saint, though. I'd much rather focus on the facts, especially those that have something to teach us today. And from all that I have learned about the Celtic church, I reckon that we can learn from people like Dewi Sant. For Dewi was just one of those early 'saints' who had an amazing impact on the pagan tribes of western Britain following the collapse of the Roman Empire.

The Christians who were left in the towns were unsure of how they could share their faith with these new and rural peoples who had come to dominate western Europe by force of arms - the word 'heathen' referred to the people of the 'heath'. 

But thankfully God raised up a new generation of Christian missionaries whose place in the re-conversion of Europe has been given much more prominence in recent years. As a result, they have a lot to teach us about how to reach those who have little or no contact with the church, and whose culture is completely alien to the one that has shaped our nations for centuries.

For, as I understand it, the Celtic church was more of a movement than an institution, and one that was characterised by a particular form of monasticism. That word can easily confuse us, however, because they were not monastic communities in the way most of us have come to think of them. They did not exist to help a select group of people withdraw from the world. They were communities of ordinary people within which everyone played a part, and they existed as much for those who did not belong as for those who did.

They had a rhythm to their day, of course – they worshipped and they studied. And they worked hard too. In fact, it's said that David would not allow his monks to make animals work for them. He made them pull the plough themselves, saying "every man his own ox".

Everyone used their gifts, whether that meant copying manuscripts or herding cows, and they sought to live the alternative life - lives free of aggression, greed and violence. They passionately believed in the team. They inspired and encouraged one another, offering and modelling a radically different way of life.

But, as I see it, the most inspirational feature of these early Celtic communities was their focus on those who did not belong to them. For, rather than condemning and erecting barriers (as churches can so easily do), they did all they could to engage with non-believers and make them feel welcome.

In recent times, churches have tended to welcome people into their churches only after they have responded positively to their message. The Celts had a very different approach. They invited people to experience something of their communal life because they believed it would get them asking questions and make them thirsty for what they had to offer. Put simply, they were convinced that a sense of belonging would ultimately result in people believing.

I am totally convinced that given the fact that there are so many people who "don't do God" in Britain today, the church would do well to adopt this kind of approach. It allows people to discover faith at their own pace, rather than feeling pressured to take a decision at a one-off special event. But then I might be biased. After all, it's how I came to faith myself.

Rob James is a Baptist minister, writer and church and media consultant to the Evangelical Alliance Wales. He is the author of Little Thoughts About a Big God.