Bowing shows reverence, honor, and worship. It is done at different times in the Divine Service.
We bow to the altar when we enter the chancel. We bow to the altar when welcomed to the Table of the Lord. This bow is an act of reverence to Christ now present in Holy Communion. We bow to Christ after we have received His body and blood.
We bow at the Name of the Trinity at the end of the Introit in reverence and honor when the Gloria Patri-“Glory be to the Father and to the Son and to the Holy Ghost” is chanted. We bow during the Nicene Creed at the words “And was incarnate by the Holy Spirit…and was made man”. This is to show reverence to the Incarnation.
Whether we sit, stand, kneel, or bow, all these things serve as devotional aids. They are things we can incorporate into our lives to help give expression to the love of God that is born from faith in our heart. They are beautiful aids that have been a part of the Church for thousands of years.