It would have been the last thing they expected.  They thought this was their chance to discredit him on a point of law they thought was safe ground.  He put them in their place, though, good and proper.

It is not the healthy who need a doctor, but the sick. But go and learn what this means: “I desire mercy, not sacrifice.”  For I have not come to call the righteous, but sinners.

The Pharisees thought Jesus was making himself unclean by eating with sinners in the house of a tax collector (Matthew 9:9-13).  But he showed a much deeper understanding of the law than they had previously grasped.  Jesus speaks to them words with a resonance from long ago.  He reminds them of the prophet Hosea’s rebuke to the people of Israel who believed they could fob God off by offering sacrifices whilst around them their nation mocked everything that God desired.

Jesus wanted the Pharisees to think again about who their God was:  He wanted to remind them that God was the very creator of the world — to remind them that God remained interested in it, the whole of it, not just the bits labelled “religious practice.”  Jesus looked at the world around him and saw sickness in need of a doctor. He wanted God’s people to wake up and realise that’s what they were for.

In the same way, some Christians today seem willing to confine their faith to religious practice, seeing no application for it in the realm of commerce, and avoiding politics as something unclean.  Yet, you can’t read the book of Hosea, or Micah, or Isaiah, or any other prophet and come out believing anything other than that God is intimately concerned with how equitably we conduct our business, and how just we make our society.

The heads of our leading and emerging economies meet in London on April 2 when the U.K. hosts the next G20 meeting.  On the agenda is a set of measures designed to bring about world economic stability, but perhaps what is really needed is world economic change.  The summit takes place against the backdrop of the worst financial crisis in generations: Major institutions have crumbled, markets have failed, and trade has ground to a halt.  And many would argue that the crisis highlights something bigger: the failure of an ideology.

The global financial crisis demonstrates to us just how connected this world of ours is. And where the pursuit of narrow interests — whether by reckless traders or self-interested nations — gets us.

This global financial crisis is less a failure of markets than a failure of values.  But it could be so different.  At the turn of the millennium, almost 200 world leaders set out a bold vision for the creation of a world founded on different values.  In signing the Millennium Declaration, these leaders recognized that the benefits of globalization must be shared amongst the many, not the few, and signaled their intent to govern not simply to serve the interests of their own nations but in a spirit of global partnership.  More than eight years later, however, there is still a huge gulf between this high rhetoric and the reality of global economics: international relations are still driven by narrow domestic agendas, international institutions are still dominated by rich nations, and the commitments made to halve global poverty by 2015 are on course to become broken promises.

As these leaders meet at the London summit, amidst the rubble of our global economy, they have another opportunity to set a course to a world based on a different set of values.  And it is at times like these when the participation of Christians in politics is crucial, because we have the blueprint for this better world.  Equipped as we are with a secure future hope in the coming kingdom, we are in a unique position to speak about the values — mercy, justice, humility — that will be at the heart of a world redeemed.  It is at times like these that the role we play has a huge influence over the world we see created around us.  At this time will we engage or retreat?

The systems and structures of our world either glorify God or they diminish God’s glory. And who is going to raise a voice and reach out a hand to conform these things to God’s model if not us, God’s people?  If God’s people avoid the world of commerce and do not engage in politics, then what hope do we have?  This sick world needs a doctor and that’s what we’re for.

Andy Clasper is executive director of Micah Challenge U.K., part of a worldwide movement of people speaking out against the injustice of global poverty. Over the coming months Micah Challenge U.K. is running a prayer campaign called Rise Up, calling on Christians worldwide to rise up in prayer for a better world.