Catholics often refer to the "Church Suffering," which is also called the "Church Penitent."
At first glance it may seem like a reference to the Church on earth, as we live in an imperfect world that is full of suffering.
However, the Church on earth is called the "Church Militant."
What is the Church Suffering?
The Catechism of the Catholic Church explains that there are “three states of the Church … at the present time some of his disciples are pilgrims on earth. Others have died and are being purified, while still others are in glory, contemplating ‘in full light, God himself triune and one, exactly as he is'” (CCC 954).
The Church Suffering refers to those who have "died and are being purified."
After having struggled on earth to follow Christ’s army, those in need of further purification before entering Heavenly bliss make up the Church Suffering.
This stage of further purification is more commonly known as Purgatory and is the “washroom of Heaven” (as C.S. Lewis put it), which cleanses any sins or earthly attachments before the soul embraces the joys of Heaven. The members of the Church Suffering rely heavily on the prayers of the Church Militant so that they may proceed to their eternal embrace with Our Lord.
In the past souls in purgatory were often depicted as suffering intense pain in the midst of flames, which is why it became known as the "Church Suffering."
The fire they experience is actually a purifying fire and is a representation of the purification they endure.
