"Now I am become death, the destroyer of worlds."

With this memorable misquote from the Hindu holy book the Bhagavad Gita, Dr J Robert Oppenheimer summed up his feelings on the first nuclear test which eventually led to the bombing of Hiroshima and Nagasaki. He spoke of the response of his colleagues watching the events unfold, "We knew the world would not be the same. A few people laughed... A few people cried."

Who was this man who was so shell-shocked by the first aggressive use of a nuclear weapon? Not a bleeding heart peace activist, but one of those responsible for creating it – the so called 'father of the atomic bomb.'

Oppenheimer's words have echoed down through history. But look at them carefully; he wasn't saying the bomb shouldn't have been dropped – or, indeed, that it should. He was merely reflecting on the awesome power that humankind now possessed. The terrifying reality that we had the capacity to destroy each other on a scale so vast that Oppenheimer invoked the supposed power of a deity as the only equivalent.

This week Jeremy Corbyn, the new Leader of the Labour Party, said that were he to become Prime Minister, he wouldn't be willing to launch a nuclear attack. This is more of a theoretical question that a practical one; no British Prime Minister has ever unleashed a bomb and indeed neither has any other world leader since the twin attacks on Japan at the end of the Second World War. But Corbyn's willingness or otherwise to 'push the button' is being seen as an indication of the kind of leader he would be.

Britain's nuclear deterrent is one of those issues that until recently was universally accepted as a 'necessary evil' by mainstream politicians. But with the advent of the Scottish National Party (whose position is to get rid of it – describing it as "utterly irrelevant to the defence and security challenges we face in the 21st century") and now Corbyn's election as Labour Leader – as a country we are beginning to debate whether we should retain the ability to kill tens of millions at the push of a button.

This leads to a wider question. Not about the affordability or efficacy of the Trident system itself, but a much more substantial issue. Should nuclear weapons ever be deployed again, and if so, would we be willing to push the button and face the consequences?

There are powerful arguments both for and against. First, the arguments in favour of being willing to launch a nuclear attack. The clue is in the name of the nuclear 'deterrent.' Having a nuclear weapon in this view isn't so much an aggressive act as an insurance policy – others won't use theirs because they know we have one to use in return. This led to a state of affairs during the Cold War known as MAD (Mutually Assured Destruction) that arguably prevented the use of nuclear weapons by either side – even when relations were at their most fractious.

Of course, the use of the bomb as a deterrent is undermined by a leader saying that it wouldn't be used. It saps the deterrent of much of its power and leaves it as a costly white elephant.

Another argument in favour of pushing the button is simply this: we should practice what we preach. So if we live in a world where nuclear weapons are a reality and we have them, we should have the integrity to be willing to use them – aware of the dreadful consequences. The genie can't be put back in the bottle and until such time as the number of nuclear weapons in the world is vastly reduced, there is an integrity to being willing to unleash our own as a last resort.

Another simple, consequentialist argument for maintaining and being willing to use nuclear weapons is that to do so is to be able to save lives. There is a debate as to whether more died in the bombings of Hiroshima and Nagasaki than would have perished had the War dragged on. But one reading of the 70 years since then is that peace has been maintained simply because of the willingness of British (and American) leaders to drop the bomb if attacked.

But what of the arguments against? Well let's start with that last point. There really is no way of knowing how many would have died in the remainder of World War Two had the nuclear bombs not been dropped. But a utilitarian case that suggests the greater good has been served doesn't stand up well when looking at the utter devastation and ongoing consequences for the lives of millions of innocent people.

Secondly, there is much doubt over whether the theory of Mutually Assured Destruction holds any more. During the Cold War, the only way the use of nuclear weapons would have been sanctioned was by Washington or Moscow. Despite coming perilously close during the Cuban Missile Crisis, sense prevailed and the two superpowers didn't unleash carnage. But what of today's threats? Since the end of the Cold War, control of nuclear weapons is now in the hands of eight countries (nine if you include Israel, which denies it but is thought to have them). But more worryingly, it's now possible for dissident and terrorist groups to attempt to get hold of nuclear weapons. The disintegration of the Soviet Union and the unrest in Pakistan are just two of the potential ways in which a non-state group may have managed or may manage to acquire a nuclear weapon. In this case, Mutually Assured Destruction goes out of the window – if the UK was attacked with a nuclear weapon by a non-state group, where and how would we hit back? A willingness to use our weapons is of very little use against a mobile terrorist group.

Thirdly, there is a very simple consideration for us as Christians. What does our faith have to say about the use of a weapon of mass destruction? The Ten Commandments would seem to rule it out. "Thou Shalt Not Murder" may not be an absolute prohibition on killing, but the number of innocent people who would inevitably be killed in a nuclear attack would surely fall foul of this commandment. St Augustine's theory of Just War demands that (in the words of the Catechism of the Catholic Church), "The use of arms must not produce evils and disorders graver than the evil to be eliminated." In other words, just because a country has been attacked, just because it may be in a state of war, it isn't acceptable to cause the level of suffering that a nuclear strike inevitably would.

Moreover, the words of Jesus seem to make use of nuclear weapons very, very difficult. In Matthew chapter five Jesus says, "I tell you, do not resist an evil person. If anyone slaps you on the right cheek, turn to them the other cheek also." This clear injunction from the Sermon on the Mount leaves Christians very little room to argue in favour of launching a nuclear strike – even after provocation.

For the first time in many years, the debate is back on the table. And as with all contemporary political discussions, the world urgently needs to hear the voice of Christians. While the answers aren't easy, we shouldn't shy away from this important issue. The future of the world may well depend on it.