Is an attack against the Christian teaching of marriage (in revolutionary terms, the L’Ancien Régime) an attack against the liturgy of the Church? Yes, the liturgy.
Pope Benedict XVI in his book on liturgy, A New Song For the Lord”, writes,
“Liturgy, however, is a whole made up of all the sacraments, and if an essential part of the whole becomes sick or almost becomes extinct [referring to Penance here], then the entire liturgy and all the other sacraments are at risk.”
Add to this Pope Benedict’s earlier statement, “How we attend to liturgy determines the faith and the Church” and we can surmise the following:
The Church “and” its liturgy (how it worships and understands God) is under attack by the secular laws which legislate against natural marriage.
Connected in this way, if we humbly worship God and participate in a Mass faithful to liturgical norms set out by the Magesterium, we help strengthen an effective bulwark against the forces which attack the nature of marriage, the nature of man, and Holy Mother Church.