AID to the Church in Need is a charity which works to protect the rights of Christians and to support the suffering and persecuted Church.
It points out that today, Christians are the most persecuted people in the world, with religious freedom in decline in many countries.
To help highlight the plight of persecuted Christians and those martyred for their faith, it runs an annual 'week of witness' campaign, with the Wednesday of the week marked as 'Red Wednesday'.
ACN Ireland says it is an opportunity to "stand in solidarity with, and bear witness to the heroic example of, our persecuted brothers and sisters in faith across the world".
Christians in more than 95 countries face daily persecution for their faith, says ACN, with an estimated 80 per cent of all acts of religious persecution committed against Christians. It says that 245 million Christians are "facing extreme persecution".
This year's week of witness runs from November 25 to December 1, with Red Wednesday falling on November 25.
St Patrick's Cathedral in Armagh has been bathed in red light in recent years on Red Wednesday to raise awareness of the campaign.
The charity suggests that people can also wear a piece of red clothing - "as a mark of the blood lost by Christians all over the world in defence of our faith" - and pray "for the suffering and persecuted Church".
ACN says that Red Wednesday is "an opportunity for the faithful to gather as a community of witnesses - even if these days this is only possible electronically, we can always unite spiritually in Christ - and pray not only for persecuted Christians, but also for the persecutors of Christians".
People can be "a vibrant example of the beauty and dignity of Christian culture as well as a witness to the reality of the historic and current oppression and martyrdom of Christian peoples globally", it says.
More information and resources on Red Wednesday can be found here.