It was the late Irish-American Congressional Speaker Tip O'Neill who said that 'all politics is local'. And he was right.

At local election time like this, it is issues like pot holes, speed bumps and council taxes that come to the fore. Ordinary people do not follow the games of who's up and who's down in Westminster with the fevered interest that political hacks do. Which is lucky for both the main parties, for at a national level, they are in disgrace. The Windrush scandal has exposed a conscience-free government machine denying citizenship to some very British people who came to these shores to help the country in the wake of World War Two. And Labour's antisemitism problem has shone a light on the murkiest side of sectarian party politics, with cases of blatant discrimination based on race and religion. In this climate, you could be forgiven for thinking: why bother voting?

But to borrow Tip O'Neill's mantra, all politics is Christian, too. For if we are all connected, part of the body of Christ – and neighbourliness runs through the New Testament – then what we do affects others, and we must engage with 'the system'. For the majority of us who are not hermits, this means living out our faith in the world, with all its rough edges; it means going out and acting in the margins; and it means voting and being known to have voted.

Here are three reasons why Christians should vote today.

1. It is part of the mission of Jesus

'Love thy neighbour' is central to the teaching of Christ, and we have a duty to help others around us. In practical terms this means engaging in their desires and fears, hopes and dreams. In Luke 4: 18, Jesus is quoting Isaiah when he says: 'The Spirit of the Lord is on me, because he has anointed me to proclaim good news to the poor. He has sent me to proclaim freedom for the prisoners and recovery of sight for the blind, to set the oppressed free.' But Isaiah itself is widely held to be prophesying the mission of Christ himself, and a very practical mission it was. Jesus didn't just teach: he reached into the ground, rubbed earth into men's eyes, and healed. His miracles may have been symbolic, but they were real and practical, too. And his message of love for your neighbour starkly applies to many elements of politics today, from immigration and asylum, to food banks, to tax and spend.

2. We are part of society

At a recent talk at St Mary's University, Twickenham, about the environment, Rowan Williams, the leading theologian and former archbishop of Canterbury, surprised some in the audience by pointing out that even trees communicate with each another when they are under threat. If organisms like trees are cosmically connected, just think how connected we humans are with one another. Williams has been among those who points out that when one of us suffers, the whole body of Christ suffers. So we must recognise our duties to others. To quote Jeremiah 29: 'But seek the welfare of the city where I have sent you into exile, and pray to the Lord on its behalf, for in its welfare you will find your welfare.'

3. It is a good Christian witness

As Jesus says in Matthew 5:16, 'let your light shine before others, that they may see your good deedsand glorify your Father in heaven'.

Christianity is not just about retreating, closing the door and praying; this faith is also about setting a good example. Equally, Christians should not be mere culture and keyboard warriors, ranting and raving about how society is going to hell in a hand-cart. It is about getting out into the world and acting, changing and shaping that society for the better. Whether conservative, leftist, liberal or other, we all have something to contribute. And by voting, you are standing up and being counted among those who are engaging on what remains, for all the cynicism around and for all its faults, a relatively un-corrupt and democratic system. Jesus never advocated the political revolution that many through the ages have sought; and attempts to create utopia on earth in the Soviet Union, North Korea and elsewhere have failed. We have the system we have, and though many are alienated from it, not least thanks to the ongoing scandals, widespread apathy is a myth, and there is a distinction between the two.

People care about matters that affect their everyday lives. So show them that you are voting – for their sake as well as your own – today.