Every time we pray, we not only engage our spirit, but also our body. This is because we are humans and were made by God in a union of body and spirit.
The Catechism of the Catholic Church clearly lays out this principle in its section on prayer:
The need to involve the senses in interior prayer corresponds to a requirement of our human nature. We are body and spirit, and we experience the need to translate our feelings externally. We must pray with our whole being to give all power possible to our supplication.
Prayer needs to involve all of our senses. This is one of the reasons why the Mass has various "smells and bells." Mass even includes the senses of touch and taste.
What we do with our bodies during prayer has a direct effect on our soul.
This doesn't mean that every time we pray we need to have incense or meditative music, but it does mean that we should be conscious of this reality.
God made us with a body, and prayer should not be separate from our body, but include it as much as we can.
