Jesus is present in the Eucharist which the parents are denying them by not bringing them to Mass.
Education in the faith is wonderful but Mass is what it is all about.
Christ is present in the midst of 2 or 3 that are gathered in his name, he is present in the simple faith of a child...we celebrate the death and resurrection of Christ in the partaking of the Eucharist, but is in faith in Christ that we enjoy his presence!