Last week I had the great privilege of attending the annual Christians in Parliament service of prayer and worship. This was a chance for several hundred Christians involved in politics to meet together to thank God for his blessings and pray for the nation. It certainly wasn't a dry affair with a team from Bethel Church's school of supernatural ministry, who were visiting from California, leading much of the evening and offering one-to-one opportunities for prayer and prophecy. It was a meeting where God was speaking powerfully into people's lives and the Holy Spirit was tangibly present.

It was also a night of stories, with a number of people talking about how God is on the move in Westminster. Gary Streeter MP, chair of Christians in Parliament, told us that when he first entered politics in the 1980s he would often be asked how Christians could be involved in such a dirty business. Things have moved on now and he no longer hears that. There is an appreciation that government is a far too important area of life for Christians to be standing from a distance and then complaining when they don't like a decision. Christians in Parliament continues to put on events hosting well known Christian speakers with a high proportion of MPs attending having no religious faith. He was very pleased to announce too, that there has been an influx of Christian MPs joining parliament following the General Election.

The most inspiring testimony of the evening though came from a woman who works for the Department for International Development. A few years ago she had been at a Christian conference and went to a talk about human trafficking. As she heard the stories of so many lives shattered through exploitation, as she put it, 'God completely broke her heart'. She came away from that meeting convinced through the Holy Spirit that she needed do whatever she could to free people from these horrendous situations of slavery and abuse.

She went back to work and talked to her boss about it. Her department dealt with trade in Asia and as her boss pointed out human trafficking was within their remit. But the urge to do something did not dissipate, so after more prayer and hassling, her boss finally relented. They were about to go away on holiday for three weeks and told her that if she could put together a workable proposal within that time, they would see what they could do to support it. So she went to work, but quickly realised that with no experience in this field and such a small time frame, it was an overwhelming task. Having reached the point of despair and ready to give up, by chance (or rather through God's divine intervention) she had an encounter with someone who had all the expertise needed to aid her in her planning. They came together to produce a strategy that they both believed could be implemented.

When her boss came back, they gave it their full approval and began passing it up the line. It gained momentum and was eventually formulated into a new £10 million anti-trafficking programme for South Asia. It was launched by the Prime Minister on International Women's Day in 2012 with the aim of stopping 60,000 women and girls being dragged into modern-day slavery.

This is one of those stories that is so inspiring because, just like so many from the Bible, God uses an individual in a fairly ordinary position to achieve great things. It is all because they have chosen to open their heart to Him and remained faithful even when they have faced seemingly impossible odds.

Gary Streeter made the point that it will always be messy for Christians working in the environment of politics and government, but it will also be Godly. Sometimes we are led to believe that to be truly called by God, Christians should go into full time ministry as church leaders or missionaries or work for a Christian charity. This simply is not true. Christianity will never have a significant impact on our culture and society without Christians bringing God's values into the realms of business, finance, the arts, education and politics, to name just a few.

There is a huge amount that churches are doing and can do to change the world for the better, but it would take an incredible effort for the churches in the UK to initiate a programme to combat human trafficking on the other side of the world and raise millions to properly fund it. We need to acknowledge that at times God can use his people in other institutions to achieve far more than is possible just through church programmes and Christian organisations.

I came away from the evening with two questions important questions that I believe we all need to consider: Are Christians willing to have the faith that God can use them in amazing ways no matter what their job or situation is and are churches seeing every member as a missionary and ambassador for God's Kingdom, supporting and encouraging them as much as those who are seen to work 'full-time for God'?

Gillan Scott regularly writes about the relationship between Christianity and society. He is deputy editor at archbishopcranmer.com and founder of the God and Politics in the UK blog godandpoliticsuk.org. You can follow him on Twitter @gillan_scott