A few years ago, I stood in the dust of a half-built church on a small plot in northern Vietnam while the pastor excitedly recounted his plans for the building. At first glance, the building was not immediately distinguishable from the other houses nearby.

It was only when the pastor explained that this was the first of several attempts to finish the building that it became clear that this unfinished church actually represented the challenges for the small local Christian community, who were facing hostility from their neighbours and local authorities.

Despite the fact that he had the official permission for the construction, the pastor had been ordered by the local authorities to dismantle the building at least twice before, often on spurious grounds. Nevertheless, the pastor kept rebuilding his church and he was determined and hopeful that one day he would succeed.

Today, I am wearing red for #RedWednesday, an initiative by Aid to the Church in Need (ACN), in partnership with Christian Solidarity Worldwide (CSW), that aims to put religious freedom on the public agenda and to encourage people to stand up for faith and freedom.

All over the world, Christians and other religious minorities who are struggling to realise their right to freedom of religion or belief, face challenges ranging from everyday discrimination to harassment, imprisonment, threats of violence and even death. Red is the theme for the day that recognises the high price that so many pay simply for following their faith.

Later today, the Houses of Parliament in Westminster will be floodlit red in support of the day, as will Lambeth Palace and ten UK cathedrals, including London's Westminster Cathedral and others in Ayr, Edinburgh, Paisley, Birmingham, Norwich, Wrexham, Derry and Armagh.

The bright red Faith and Freedom bus will be travelling around London raising awareness of this issue and stopping off at various churches that are supporting #RedWednesday. This evening, there will be a procession with Christians carrying the cross across Westminster Bridge and into Westminster Cathedral for a service to pray for our brothers and sisters who are under pressure globally.

The scale and extent of religious freedom violations taking place on a daily basis around the world is vastly under-reported. According to the United States Commission for International Religious Freedom, the state of international religious freedom is worsening in both the depth and breadth of violations. Its new report states: 'The blatant assaults have become so frightening—attempted genocide, the slaughter of innocents, and wholesale destruction of places of worship—that less egregious abuses go unnoticed or at least unappreciated.'

On my visit to Vietnam, I heard about Christians and other religious minorities experiencing violations across the scale from everyday discrimination or harassment in their communities through to imprisonment and the threat of violence.

This month, CSW joined 14 other Vietnamese and international organisations in a campaign to set Vietnam's prisoners of conscience free, many of whom are men and women who have been arrested for their political or religious beliefs.

As of November 2017, there are at least 165 prisoners of conscience in Vietnam. However, due to the challenges of obtaining information about prisoners in the country, the real number is likely to be higher.

Many of those on the list belong to independent religious communities not registered with the government, including Christians from ethnic minority groups. CSW continues to receive numerous reports of violations against such groups, in particular those located in remote parts of the country, like the pastor that I met. Documented violations include harassment, forced evictions, beatings, torture, pressure to recant and detention or imprisonment. Those who advocate for freedom of religion or belief or for the rights of others generally receive the harshest treatment.

#RedWednesday is a powerful and symbolic way to show solidarity with our brothers and sisters around the world, and to stand for faith and freedom for all, defending the right of every person to be able to choose, change and practise their religion.

My enduring memory of the church I visited in Vietnam is not of the half-finished building, but of the warm, loving community that I met with and worshipped with there, who welcomed my team and I like long-lost family members. I remember their determination, joy and worship despite the challenges they faced in completing the construction.

#RedWednesday is a day for us to play our part in making a stand for faith and freedom through prayer, campaigning and solidarity with those who do not enjoy the freedoms that we so often take for granted.