CAPG's Blog 

When you enter the church, go to your place as quietly as possible. Some people make a great deal of noise in getting in their seats. This is calculated to disturb the congregation, and is exceedingly unbecoming. The church is the temple of the living God, not merely because it is dedicated to his service, but because he dwells therein. The very walls of is are sanctified. It is at all times holy, and is therefore always to be entered with the respect due to the house of God. "The Lord is in his holy temple; let all the earth keep silence before him." 

Do not walk up the aisles with an air of pride, such as the people of the world may put on in a ballroom. You may be regarded by the world as rich, intelligent, and accomplished; in the church, you are a poor, blind, and sinful being, and should come in all humility to implore the grace and mercy of God.

It is still more necessary to observe these rules, if you enter the church after Mass has commenced. If you happen to enter during the elevation or communion, kneel by the door, and remain there during the more solemn parts of the Mass; you can afterward retire quietly to your place.

You should assist with attention at the holy Sacrifice. When you are not reading your prayer-book, keep your eyes fixed on the altar on which that adorable Sacrifice is offered, and never gaze around in the church.

Do not leave the church until the priest is retiring from the altar to the sacristy. Those who are the last to come to it, and the first to rush out of the church, seldom derive any benefit from Mass, and often do not hear it properly. The practice of all pious Catholics is, to spend some time after Mass in thanksgiving.

Do not remain standing before the church, as if you had no other object in coming than to see and be seen. If you have time before Mass, say the Rosary, or the Stations of the Cross; employ the time in spiritual reading, or in adoring Jesus Christ in the Blessed Sacrament.

Remember what those who have gone before you in the faith endured that they might be present at the holy Sacrifice of the Mass, and reflect with what attention and piety they must have assisted at it. During the early persecutions, no churches could be built. The divine mysteries could not be celebrated anywhere in public. The faithful were compelled to go into subterranean vaults, called catacombs, where Mass was offered on the tombs of martyrs. The candles we burn on our altars remind us of those days, and of the brightness of faith that made them days, not of mourning, but of joy.

To assist properly at Mass is one of the most important acts of Christian life; and hence the Church declares it to be mortal sin to neglect to hear Mass on Sundays or Holydays.

Source: The Holy Family Manual by the Sisters of Notre Dame, 1883