'Ah, Sovereign Lord', I said, 'I do not know how to speak; I am only a child'.[1]

There must have been a mistake. This young, sensitive and introspective priest was surely destined for a quiet life, leading and nurturing the religious believers in Judah. Could he really be 'a prophet to the nations', 'to uproot and tear down, to destroy and overthrow, to build and to plant'? [2]

In church, we often hear a call to be godly in all we do. Yet this is often limited to personal relationships with our family, friends and colleagues. Jeremiah was being called to serve God in public life, in the midst of society's raging debates. Christians today should do the same - but where do we begin?

looking at God

Our God cares greatly about how societies function. As we draw close to him, we feel more acutely his concerns for justice and equality, and his love for the poor and needy.

In the Old Testament law, we have a blueprint for how God wanted ancient Israel to run themselves. To modern eyes, much of it seems bewildering, weird or hard to understand - and certainly not very relevant to modern life. But dig deeper and you find principles that may provide answers to some of the great social problems that confound policy-makers, modern technology and the thinkers in society.

Take the issue of immigration. The Bible tells us that God's attitude to foreigners living within Israel was to be imitated by the Israelites. The Lord 'loves the alien, giving him food and clothing. And you are to love those who are aliens…' [3] They were not to be oppressed or ill-treated, [4] but they were to be specially provided for during the harvest.[5]

Yet last year, the British Medical Association (BMA) repeated their assertion that the health of asylum seekers deteriorates during their time in the UK. Many are unable to access treatment for diseases such as TB, AIDS, or for the psychological damage associated with torture or rape.[6] They often form an underclass in Britain; unable to work, living in squalid accommodation and subject to exploitation by criminal gangs. God loves such individuals and holds up principles in the Bible that will lead to their being cared for in a generous and humane manner.

Take the issue of children; God led Abraham up a mountain, asking him to sacrifice his only son. But God stopped him at the key moment, proving that he was not like the other gods of the time who demanded child sacrifices. Human life is precious to God, and there was to be severe punishment for those who offered their children to the detestable gods served by neighbouring tribes.[7] In Britain today, a child is killed in the womb every three minutes. This is because we, as a nation, follow the gods of today instead of the God of the Bible. They include career, convenience and the perfect physique.

God is characterised by his justice. We should strive for change wherever there is abuse of power - whether in healthcare rationing, international law, foreign policy or medical ethics. Looking more closely at God alters our perceptions of the world around us. As we read the Bible and learn about God's concerns, we become more like him in hating evil and striving for what is right.

looking around us

As Christians who seek to emulate God's care for all people, we should not hide ourselves from the wrong things going on around us. Rather, we should investigate and expose them, demonstrating a better way to live - a rational and truthful way. After Cain murdered Abel, God told Cain that his brother's blood 'cries out to me from the ground'.[8] Likewise, the abuses of Sodom reached God as an outcry,[9] because they were 'arrogant, overfed and unconcerned; they did not help the poor and needy.'[10]

It's good for Christians to listen to the outcry that rises from our world. The Gross Domestic Product of the poorest 48 nations (a quarter of the world's countries) is less than the combined wealth of the world's three richest people.[11] Less than one percent of what the world spends on weapons each year was needed to put every child into school by the year 2000; yet it didn't happen.[12]

In the UK, alcohol related deaths more than doubled between 1991 and 2005.[13] Rates of pregnancy and sexually transmitted infections in British teenagers are amongst the highest in Europe, and one in five abortions in the UK is performed on a teenage girl.[14] Added to these are the isolation and depression experienced by many elderly people; the relative poverty and exploitation of some single mothers; the risks and abuse suffered by commercial sex workers; as well as the racism and lack of opportunity experienced by some ethnic minorities. Injustice and exploitation extend from the slums of the developing world to our own back yard.

looking at ourselves

The theme of faith working itself out in action is consistent throughout the book of James:

Suppose a brother or sister is without clothes and daily food. If one of you says to him, 'Go, I wish you well; keep warm and well fed,' but does nothing about his physical needs, what good is it? In the same way, faith by itself, if it is not accompanied by action, is dead. [15]

Christians have a unique calling to care for those in need, and the power of God to help them do so. We are a big part of God's response to poverty, suffering and injustice.

The great need of human beings is to know, love and worship their creator. The great commission, to make disciples of all nations, was given to all Christians.16 But another great command in Scripture is to shine before men - like a lamp on a stand [17] or stars in the sky [18] - to be the light of the world.[19] We do this, wherever we are, by standing out as different. As future doctors, this means shining out in consulting rooms or ward rounds, in our medical schools, our future profession and society more broadly.

The Old Testament prophets had a rough ride. They were sent to confront kings and priests about their failure to lead as God wanted. They were to tell the rich and the poor, both men and women, that they were not living the lives that God demanded of them. Jeremiah, a timid and sensitive soul, was such a prophet, who ended up being thrown into a cistern and left to rot until his friends rescued him.[20] People do not like being told that they are doing wrong. But the great injustices in the world, be they poverty in Africa; abortion; racism; or genocide, do need to be exposed.

But the biblical message is not simply one of condemnation. Not only do we hold out salvation and the love of God, but also God's instructions for how societies are to work. We do not simply condemn abortion, we must also show how women can cope with having children at awkward times and give them the necessary support. We don't simply attack unfettered capitalism; we show people how to set up a system that allows money to be made without trampling those at the bottom of the pile.

taking action

The church, as well as CMF groups, is made up of people with vastly different backgrounds, personalities and gifts. Below are some suggestions for how we, as Christian medical students, can go about tackling some of the world's big issues. The ideas higher up the list are things that we can all do. A recent Triple Helix article discussing the use of our spare time may help you in deciding where to serve.[21]

Those of you who are particularly interested in public affairs can take things further by looking down the list. Are you the kind of person who stays up until the early hours of the morning discussing social trends? Do you enjoy going on demonstrations and waving placards? Is your favourite programme Newsnight? If so, why not commit your enthusiasm for public life to God, and let your involvement be a great witness to his love?

pray

Prayer brings us closer to God's view of the world. It means speaking to him, echoing back his words, wrestling with him and asking for his help. This is the place where we can bring our grief at injustice in the world, as well as our feelings of uselessness and weakness. It shows God our love for him and our respect for his Word. Above all else, prayer is answered:

If my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then will I hear from heaven and will forgive their sin and will heal their land. [22]

learn

Prayer can become repetitive and even boring unless there is fuel for the fire. Keep yourself informed. Keep an eye out for news, and pray about what you see. Try to develop a biblical way of looking at issues. Christopher Wright has written two excellent books showing how the Old Testament law provides moral guidance for society. They are: Walking in the Ways of the Lord [23] and Old Testament Ethics for the People of God [24] (only buy one as they overlap). There is so much in these books to encourage Christian involvement in political debate. Look also at some of the articles on the website of the Jubilee Centre in Cambridge.[25] Their political proposal, the Jubilee Manifesto, shows how a biblical view of society - with proper relationships between individuals being of prime importance - can shape a whole approach to law, business and social provision.

discuss

Look for chances to talk about these issues with friends at medical school. You can find help with what to say about medical issues on the CMF website. [26] Take the chance to discuss things that come up in your medical course. When studying sexual health, why not talk about whether condoms are really the best way to bring down teenage pregnancies?

In obstetrics and gynaecology, reading up on the negative side effects of abortion will enable you to present a more balanced approach than those who simply talk about 'women's rights'. Be evidence-based and reasonable in all you say, because there is evidence showing God's way to be the best way. As these conversations unfold, you may even have the chance to testify to how God's love has changed your life.

involve your local CMF group

Why not run a debate at your medical school on abortion, sex education, or trade law reform? CMF can often provide speakers. These debates can be a really good way of showing how the Bible is relevant to modern life. It can also be a good way of demonstrating how much more caring and compassionate the Christian worldview is compared to others. Why not get your group to visit people in local nursing homes, or to take sandwiches to the homeless?

follow leads

Are nearby Christian doctors involved in anything interesting? They might run clinics for the homeless or teach sex education in schools (see box for my own experiences). These can be good ways of helping people practically, which also enable you to understand the needs of society. Any experience of teaching sex education in school adds gravitas to what you say about the topic. But you will be able to speak about sexual health with even more authority if people can see that your lifestyle is consistent with the concerns that you voice.

write articles

Student newspapers and magazines are very often short of material, so why not write a topical article to kick off the debate? This is especially good if you already have an interest in an issue. For example, you could write about your developing world elective or your meeting with a particularly interesting patient on the ward. Alternatively, why not submit a rapid response to a Student BMJ article?

use your SSMs

As you go through medical school, more and more freedom is given to you in self-selected modules. Literature searches enable you to acquire a bird's eye view of subjects that interest you. This enables you to study an area in detail, and acquire an understanding of the challenges and opportunities it poses.

Alternatively, you could do a piece of original research. Finding something suitable may be hard. But simple surveys can produce interesting and useful results. For these more informal studies, the hassle of obtaining ethics approval is often waived. One idea is to elicit the views of health professionals towards euthanasia; my survey was on the opinion of medical students towards patients' spiritual beliefs.

use your spare time

You can often give a helping hand to those involved with public policy work in CMF by doing some spade work. Last year, students were involved in getting signatures for the petition against physician assisted suicide that was sent to Downing Street. Others counted up the signatures and collated the petition. There are opportunities to help with research backing up government submissions that CMF makes on upcoming law changes. If you are interested in a particular area, email Andrew Fergusson (andrew@cmf.org.uk), head of communications at CMF, to see what projects you can help out with.

join the BMA

Student membership currently costs £36 per year, for which you receive the Student BMJ and the opportunity to be involved with meetings at the medical school level and beyond. It is relatively easy to become elected as a representative of your medical school at the national Medical Students' Conference. From there, you can apply to represent medical students at the BMA's Annual Representatives' Meeting (see box for what we did this year).

Abortion featured prominently at this year's ARM. There needs to be more Christians arguing for clinical guidelines protecting women and unborn children, in a rational and evidence-based manner. This is just one of the many ethical and political issues on which the BMA forms policy. Let's make sure the voices of Christians are heard.

lobby Parliament

You can find out about the important things that are happening from the CMF website, your CMF student group leader, or your CMF medical school secretary. You can also look up your local Member of Parliament and email them. [27] Another website tells you how they voted on controversial ethical issues. [28] You can help inform their decisions by simply writing them an email. Just explain that you are a medical student living in their constituency, and that you would like them to vote a certain way on an issue. Provide logical reasons for your views, backed up by evidence.

Periodically, there are chances to join demonstrations at Parliament. For example, you can do this when laws on medical ethics are being debated. You can also go along and observe at select committees when doctors from CMF give submissions. There is an opportunity this autumn when the issues surrounding abortion are discussed.

listening out for God's call

Both Jeremiah and Isaiah protested, on the grounds of inexperience and inability, against their appointment as prophets. [29] When Jonah was called to confront the godless city of Nineveh, he couldn't be seen for the dust he kicked up running away to Tarshish. [30] God gives us the words to say and the strength to say them; all that we bring is a willingness to be used.

Begin small - look at the list above and see what you can do in the coming academic year. As you take these first steps, you will be amazed by how God opens up more opportunities. You will experience the joy of using your gifts and talents in his service.

Heavy involvement in public policy is not for everyone. But it is for some - so get involved. Push at some doors, and see which ones open. The need is so great and the love of God is so compelling that we simply cannot sit still and leave the world to its own devices.

Then I heard the voice of the Lord saying, 'Whom shall I send? And who will go for us?' And I said, 'Here am I. Send me!' [31]