We owe Our Lord exterior respect; that is the prayer of the body, and nothing so much helps the prayer of the soul.
See with what religious care the Church has regulated the least details of her exterior worship. It is because this prayer gives great glory to Jesus Christ. He gave us the example of it by praying on His knees, and tradition shows Him to us praying with His arms in the form of a cross, or raised toward heaven. The Apostles preserved for us this manner of prayer, and the priest uses it in the Holy Sacrifice. Our body, which receives life from God, which lives upon His benefits at every instant, does it owe nothing to God? It must be made to pray by its respectful posture. Negligent attitudes of the body weaken the soul, while a crucifying one strengthens and helps it. I do not wish to make you suffer by a too uncomfortable position, but we must use a little severity.
Never indulge in familiar postures before God, for they engender contempt. Love Him, be tender and affectionate toward Him, but never familiar. Aridity and indevotion in prayer almost always rise from irreverence of demeanor. If traveling, or saying prayers of supererogation in your own homes, take the posture that will fatigue you least; but before Our Lord, the whole being should adore. Recall how severe God was on this point in the Old Law, through what preparatory details the Levites had to pass. God wished thereby to make them feel their dependence and to prepare them to pray well. Through want of this exterior respect, our piety languishes. I know well that it is not necessary to tremble with fear before God or to be afraid to enter His Presence; but on the other hand, we must not look as if we ignored Him. This reserved demeanor is a help to more earnest prayer, but, through sensuality, we neglect to maintain it. We think ourselves too much fatigued. Ah, how the imagination deceives us! If the Pope were passing, our fancied fatigue would not prevent our kneeling. And even should we be seriously fatigued, let us not be so afraid of suffering, for it spreads the wings of prayer! We can at least, even then, preserve a grave and serious demeanor. When persons of the world are fatigued, they sit down in an upright position; they do not lounge on their chairs. Take, then, none of those postures that relax the soul and unfit it for prayer. As for us, religious, kneeling is our proper position, for it is the true posture of the adorer. If we are greatly fatigued, let us stand. That, too, is a respectful position. But let us never sit. Let us be soldiers of the God of the Eucharist. If our heart is not burning with love, our body, at least, will testify to our faith, and our desire to love and do the right thing. May our body pray! May it adore! Let us all belong to the Court of King Jesus. Think that the Master is there. Impress your mind with that thought. Attention to Our Lord Jesus Christ!