My family has a history of participation in evangelism. In the 1920's in Cardiff the non-conformists, and the 'Plymouth Brethren' in particular, were known for their evangelism, not only in their chapels, but also on the streets with their open air meetings. Each open air meeting, often on a corner where there was a pub, was held simply to preach the Gospel to sinners.  It was a combination of Bible readings, hymns intended to speak to the sinner and of course short sermons in which the listener was warned of an eternity in hell in the absence of penitence - and all this without the aid of amplification.  My uncles had very strong voices. Those preaching were entirely convinced of the truth of their message and wanted to make a difference, for the better, in the lives of others.

We have 650 MPs in the Commons of whom 290 are a part of the opposition and therefore have a limited role in political life. It is very difficult to make a difference without access to power and the government has almost all the power. There are perhaps 150 MPs who have a role in government, but there are very few of them who actually exercise real power. As we know, even the members of the cabinet are not all equal. The other day I heard a discussion between some ex-MPs who never made it to ministerial rank. They spoke of their feeling of uselessness. They wanted to change the world, but they knew that, in reality, they were only there to vote as the government - i.e. a few of their colleagues - had decided they should vote.

And when one thinks of who amongst all the politicians has made a real difference - for the good - there are not many whose names come to mind.  Lloyd George, a liberal, laid the foundations for the welfare state in 1910 with his 'Peoples' Budget' against the determined resistance of the rich.  Winston Churchill was instrumental in the winning of the second world war and the economist William Beveridge and the labour politician Aneurin Bevan were responsible for the creation of our national health service.   Margaret Thatcher reduced the overweening power of the Unions.  Tony Blair made a difference in Kosovo and some unwanted differences in Iraq.  Obviously Gordon Brown abolished Tory boom and bust.   Dave decided to intervene in Libya: at the time it seemed to be for the better.

But notable successes are rare and there is almost always the involvement of a large element of luck - to be in the right place at the right time. Nor is it possible to be sure that one has succeeded in changing things for the better until many years after. Life is just too complicated to be able to predict.

We are not a country which needs to change in ways as fundamental as others such as Libya, but each country has aspects of its political scene which are not satisfactory.  So as an individual what can I do?  Try to become a minister or prime minister and the person whom history will judge to be a success?  Or decide not to gamble on something with a probability near to zero?  Which means that for the great majority of us, 'to make a difference' is limited to the things with a more local impact or otherwise more limited in scope - whether as part of an organisation or not, by e-mail to your MP or to the appropriate Minister; giving financial aide to your preferred organisation, talking with your friends.or even via a blog.

At root, as human beings we have a sense of fairness.  And it seems to me that, for the most part, it is this desire for fairness which provokes the demand for change: for example to the laws which punished people simply for being homosexual or by the creation of a national health service.  But in each case it was necessary in the first place to see things more clearly, to see the fact that in the real world homosexuality was not a perverse choice, but a normal condition for a minority; that most of the poor are not poor by choice or through a failure to assume responsibility for themselves.

And I am not convinced that it is often the politicians who dare to grapple with the realities of life.  They fear upsetting the electorate and so they mostly react to what they believe to be the (often short-lived) mood of the country.  Of course, no one person should have the right to have more influence over the government than any other person simply because they are rich or know the right people.  But it is certainly a part of our system that, for someone with the motivation necessary, it is acceptable, indeed desirable, to try to influence government.  That the majority choose not to do so - through apathy - is not a barrier to others trying to bring about change.   It is for each one of us to decide if he or she wants to be that rather curious object, a secular evangelist.   Each of us though has a duty to pay a lot of attention to the facts before arriving at an opinion, and particularly when we are trying hard to persuade others that things need to be changed.