The Altar or the tabernacle as also known in modern times is the focal point of the Church building. It is the material expression of the Church’s worship. When a large church or cathedral was built, it was always the sanctuary that went up first.
The altar not only marks the place of the Lord’s sacrifice but the tombs of martyrs and saints as well. We see in the early Church enormous efforts made to construct altars and churches directly over the graves of the holy ones. The basilicas dedicated to Peter and Paul are the most important examples of the growth of this practice.
Today we don’t have the physical assaults on the Church that occurred in the Reformation. Yet there are still many anti-Catholics and non-Catholics who see the altar as a stone thing which is idolatrously venerated with bows, genuflections, incense, and even kisses.
Sometimes as Catholics we take the external objects used in the Church for granted. This leaves us unarmed when we are confronted with questions and arguments. A right understanding of such externals as the altar and an ability to explain them to non-Catholics can be powerful weapons.
The word “altar” means a raised or high place. Like we see in Scripture the equivalent expressions “table,” “Lord’s table,” and “place of sacrifice”. It is a place of consecration and sacrifice, where God meets mankind. It is a symbol of God’s presence.
According to Gregory of Nyssa: “This altar we stand is by nature only common stone, nothing different from other stones, whereof our walls are made and our pavements adorned; but after it is consecrated and dedicated to the service of God, it becomes a holy table, an immaculate altar.”
We see this in the Bible. Noah built an altar to God (Gen.8:20), as did Abraham (Gen.12:8) and Solomon (2 Chron. 4:1). The central purpose of the Temple was the altar of sacrifice. In the upper room, the table used at the Last Supper becomes an altar.
In Revelation the heavenly altar is described thus; “underneath the altar the souls of those who had been slaughtered because of the witness they bore to the word of God” (Rev.6:9). This is not just evidence of the Church’s practice in the first century but becomes a model.
Given the relatively fixed number of martyrs and the growing number of churches, pieces of relics were taken from their original tombs and given to new churches to be included in their altars. This practice continues. The altar is consecrated and marked with five crosses symbolizing the five wounds of Christ. Typically within the altar are sealed relics.