There is only one inner direction of the Eucharist, namely, from Christ in the Holy Spirit to the Father. The only question is how this can be best expressed in liturgical form.

Joseph Cardinal Ratzinger, 1986

There continues to be considerable misunderstanding of ad orientem worship by many Catholics, which is unfortunate, because there is so much depth of meaning and rich theology involved in the simple gesture of the priest facing the same direction as the people during Mass. 

For some, the misunderstanding can even result in anger. How did we get to a point where a Catholic would be offended by, and even leave his or her parish over, a practice that was nearly universal throughout the entire Church, East and West, for the better part of 1,900 years? Yet here we are. 

For those who are seeking to better understand the “why” behind ad orientem, this article published by Catholic World Report explains in some detail an aspect that is often overlooked, even by advocates: the eschatological dimension. That is, our great anticipation of our Lord’s Second Coming is reflected in our facing “toward the East” together with the priest during the Eucharistic rite.