Very occasionally, a prominent Christian uses their hour in the spotlight to talk about the utter centrality of their faith. At that one moment when every eye is fixed on them, they choose to sacrifice personal glory, and instead glorify God. Kaka and the rest of the Brazilian football team did it when they won the 2002 World Cup, stripping off shirts to reveal 'I belong to Jesus' t-shirts at a point when no camera dared look away. Various actors have done it, bringing awkward silences to award ceremonies as they thanked God alongside their producer, sometimes at sermon-esque length. Now Tim Farron has done it too, stunning the political world by name-checking his devotion to the Almighty in his resignation from political party leadership.

Farron couldn't avoid talking about God in his speech, given that his faith was the very reason behind his resignation. Having been hounded throughout the recent election campaign – and before it – about the relationship between his religious and political views, Farron stepped down because he believed that the conflict between the two had made his position untenable. Since the most notable area of theology which he had been interrogated about was around human sexuality, some LGBT-affirming Christians will feel offended that his faith is so apparently illiberal. Yet whatever you think of his theology, and of his decision, there's no denying that Farron's statement demonstrates remarkable integrity, and also offers a huge personal challenge to every person who calls themselves a Christian first.

As he closed his speech, he said:

"I joined our party when I was 16, it is in my blood, I love our history, our people, I thoroughly love my party.

'Imagine how proud I am to lead this party. And then imagine what would lead me to voluntarily relinquish that honour.

'In the words of Isaac Watts it would have to be something 'so amazing, so divine, (it) demands my heart, my life, my all".'

That final, stunning line is taken from Watts' magnificent hymn, When I Survey the Wondrous Cross. It's extraordinary that Farron chose to use it as the sting in the tail of his widely-reported speech. Instead of closing by reflecting on personal achievement, or landing another jab at the reeling government, he instead took the opportunity to share his testimony on a national and international scale. What could be so big, so important, that it would cause me give up the earthly thing I love the most, my life's work, the thing I'd invested in daily since I was a teenager? It's a tantalising, deeply provocative question which he has left hanging on an international canvas, reported in every media outlet in the UK, and many around the world. He didn't just resign, he evangelised to a nation.

Many things will be said and written about Tim Farron in the coming days. Some will undoubtedly focus on whether his thinking is flawed, and indeed whether it's really possible for a committed Christian to hold such a high public office any more. For me though, the statement provokes one huge challenge: could I do what he has just done? Could I reject personal compromise, and so forfeit my personal ambitions? Could I throw my life's work under a bus for the glory of God?

The Bible frequently calls us to this standard of course. Jesus tells his followers that they must become the very last and the servant to all (Mark 9:35), and take up their own crosses to follow him (Luke 9:23), while he famously tells the rich young man to give up everything he has (Matthew 19:21). Paul and the proverb-writers frequently call us to a high standard of humility. But honestly, do we really take that stuff seriously? To the point that we'd put down years of hard work, our financial security, much of our influence, just because we think our faith demands it?

Tim Farron will of course be the centre of national attention for a few more days, but soon his name and story will fade. He'll almost certainly be on the Christian conference speaking circuit before long, while his party elects another leader and politics moves on. Of course, he knew that when he made his decision. It's the very reason he used his greatest moment of influence to such effect.

I guess most of us hope we will never be put in such a position. The UK is still a relatively free country in which to practise a religious faith, especially if you're prepared to make a few compromises. Yet occasionally – and perhaps even increasingly – Christians find themselves in a position where they must choose whether to honour their beliefs or assent to their culture. So I can't help but put myself in Farron's shoes. Could I put my faith first, whatever the cost? Could I take a bullet – literal or otherwise – for my God?

As Farron so brilliantly put it, the question really boils down to this: is my view of God so amazing and so divine, that it means he demands my heart, my life, my all? When I sing Sir Isaac Watts' rousing anthem in the pews, I certainly believe it is. The challenge for every Christian is whether that translates to the sharp end of real life, if and when we're really called to sacrifice everything for Him.

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