The pro-euthanasia lobby has been very effective (up until recently) in promoting their message of 'compassionate relief of unbearable suffering'. They have succeeded in gaining the support of the general public, which, some polls suggest, is 82% in favour of a change in the law. Thankfully, and mercifully, the House of Lords has thrown Lord Joffe's bill out (as reported on pp4,5). But what if he and the Voluntary Euthanasia Society (VES) do succeed in the future and make 'dignity in dying' spell euthanasia as an option for all patients?

In one way, for the Christian doctor, things will be no different. You would still understand ethically and biblically why it is wrong for you to intervene actively to take another human life. You would know that offering time, love and multi-disciplinary care to the sick and dying is still your main concern, despite having to face up to the real fact that in some cases, the drugs don't always work and cure is not always possible.

In another way, the whole landscape of medicine in the UK would have changed. Currently patients can go to a hospital in this country knowing that the doctor caring for them has sworn 'first to do no harm'. But if you transform the role of doctor into care giver, for only as long as expedient, then we terminate you – what then? Some patients may really want euthanasia to be medicalised; it is clear some are prepared to travel to Switzerland even now to die at the Dignitas clinic. But what about the vulnerable old granny who is dementing whilst her children want their share of the inheritance now? What law can protect her once it permits medics to become angels of death?

Even the doctors who don't want to be involved will be assumed to be part of the profession that sanitises legalised killing. If the law is changed, euthanasia will no doubt become a live treatment option for everyone. Just as the 1967 Abortion Act has impressed upon every GP consulting with a nervous pregnant woman the possibility that she may actually be considering an abortion, whereas previously we could assume she would naturally carry her pregnancy until term.

What shall I say and where does my responsibility end? Firstly I must make it clear to my patients that euthanasia is not something I agree with or am prepared to refer for. I need to do this with gentleness and respect. I may be met with some angry responses. However, I suspect most patients, and especially the vulnerable, will actually be relieved to know that they will be safe from that threat in my care.

Secondly, there will be colleagues who have been convinced by the VES arguments of compassion being the highest moral code, who believe allowing patients to live out their lives and deaths with their autonomy unchecked is utopia itself. Anyone who is not prepared to march with them on their moral crusade will, in their minds, be a betrayer of the profession. And of course, you will have left more of the dirty work for them to do; that in itself will rile their consciences.

First principles of ethical debate will be useful. We accept, do we not, that a consultation should be neither completely doctor-centred (far too paternalistic) nor completely patient-centred (they do not always understand what is in their best interests, or the consequences of their decision on someone else's life). Autonomy for one has to be limited by the need for justice to be served up for the community one is surrounded by.

Unfortunately some will start to argue for the benefit to society of moving the resource-consuming patient on to a better place. If you don't believe me go to an antenatal clinic and see how much money is spent on preventing babies with Down's syndrome from entering the world. We need to show them that a person's worth is not measured purely in terms of economic productivity. God loves us in spite of our faults, whether they be physical, psychological or spiritual.

Some arguments will not be won verbally. God will expect you to walk the walk as well as talk the talk. We will have to pray harder than ever and go to work ready to face the persecution that comes. Over time you will see colleagues challenged by the time and effort you put in with your patients, how you value them and their families and seek to demonstrate God's unconditional love in a fallen world.

I hope and pray that none of this becomes a reality. The work that Care not Killing has done so effectively will need to be continued until Lord Joffe retires and beyond. But if we do fall asleep on the job, he may yet win. Remain watchful, pray continually and fight the battle.

I am not going to set another enigma as I believe the time is right after four years to pass on the baton. I would like to thank those who have written in with answers. I hope the groups that have used them in discussions have been encouraged. I myself have come across most of the problems that I have written about. Even on the day I wrote this last Enigma, I found myself contending with the complaints of a patient who wanted me to support him in his quest to become a woman. I don't know what level it is going to go to yet, but I pray that God will give me wisdom.

I trust that as you go on in your career, having thought and prayed these difficult and real issues through before you meet them, you will be able to stand firm with the belt of truth fastened firmly around your waist.

For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. (Eph 6:12)