The separation of church and state in an ever-changing society will always be a complicated matter, and has been ever since the idea was new.
It remains one of the most universally accepted principles in a democratic system.
Accepting, as we do in Europe, the pluralist and multicultural character of the European society today, the question arises: What should our understanding be of the relationship between the state and, as some see it, organised religion?
The first is one where the state gives official recognition to one particular religion or church.
The second is a non-confessional system, where the state is separated from religion and assumes an attitude of neutrality towards all expressions of religious belief or practice.
Third is the situation where the state is officially atheist.
Many are wary about the involvement of religious leaders and houses of worship in partisan politics. History has taught us that whenever the church gets too cozy with government, the church loses its prophetic voice.
Religion is the emerging political language of our times and has emerged as a new global language, also because both Europe and the United States on one side and al-Qaeda on the other see themselves as locked in a cosmic struggle between good and evil.
When they insist the world is either for them or against them, they risk political and social struggles everywhere being redefined as religious battles.
The politicisation of religion in Iran and Iraq has wreaked untold havoc on these two countries. In Northern Ireland, the Catholics and Protestants struggled for political liberation together until some politicians began to use religion to divide the two groups.
The attacks of September 11 2001 forced the world to look at the role that religion plays in politics, foreign policy and our everyday lives. It is a trend that was lying in plain sight that we can no longer ignore.
Religion, when inserted into the political arena, tends to have gruesome consequences.
Even in Europe, which introduced the separation of church and state, religion is taking on a new significance through the political expression of Islam.
The media are full of religious stories, often concerning witchcraft and frightening spiritual experiences. Stories like these are political comment by people who believe that all power has its ultimate origin in the spiritual world. Consequently, they consider spiritual and political power to be connected.
There should be a divide between religion and state. The state should govern with its policies, which might be acceptable to the religions.
Religion should serve as an inspiration, spiritually and morally. It should also serve as a reconciliator, as teacher to its faithful and as whistle-blower where the government fails to deliver or humiliates its citizens. Religion should remain impartial.
The separation of religious from political thought was invented in the West and exported to the rest of the world in colonial times. Most Westerners think of religion as a matter of ultimate meaning. They believe in invisible forces that govern our lives.
In this view, the manipulation of spiritual forces is essentially no different from speculation on international stock markets.
In both cases, gains and losses depend on interaction with an invisible force. The spirit of capitalist enterprise was originally associated with a religious view of the world.
Such efforts to navigate the intersection of faith and politics are helping to shape high-profile debates over issues ranging from abortion to stem-cell research.
Within Europe, the pattern of separation between state and church prevails. But even where this prevails, it is usually accepted that religion has implications for the public life of a state, and these may be recognised on a legal basis.
Many Catholics in the US are angered by their church’s hierarchy meddling in politics. On the other hand, there is a sense of comfort among others that bishops are taking a stand on an issue like abortion that has become so firmly fixed in the American landscape.
There is a range of faith issues alive in the US today: the role of Christian values in the presidential elections, public use of religious symbols and the American response to the rise of popular Islam.
It is important in matters of faith not to try to gloss over differences, but to recognise that the way in which believers understand the world through the prism of their faith is very much at odds with other faiths, including the faith of secular humanism.
The art is not to deny the differences or to seek to sanitise them culturally, but to strive to live with them.
A secular society needs to recognise that it is a way to keep both God and differences as part of a tolerant nation and leave God to do the condemning.
The reformer Martin Luther loved to tell the fable of the dog running along a stream with a bone in his mouth. Caught by surprise when seeing its own reflection in the water, the dog dropped the bone into the water, thus losing both the bone and the reflection.
This is a fable that resonates with the current debate in the US as well as in Europe, that people should not lose the reflection of faith in their society.
What the faith debate in Europe should determine is whether Europe will continue to recognise that it is one nation under God, not purely a secular construct.
We all need to take a step back and, like CS Lewis, realise that it is not God who should be in the dock in this faith debate, but humanity.
Politicians may encourage such a stark approach as a way of gaining support. This suggests that a fine line be walked by those who say faith has a valid role to play in public life.
We see an unprecedented secularism of European life in which some people think that any issue that is connected in any way to a person’s religion cannot be discussed in public life.
Religion is simultaneously a way of understanding the world and relating to other people. These are important ways in which it is allied to politics. This fact alone should impel us all to understand this new idiom. Too many seem more interested in fostering a divisive competition between church and state.
We should not only think of separation or mutual tolerance, but also of a relationship between state and religion that is more dynamic and creative.