Complex sentence: The Liturgical Movement has been called, superficially, a'catching up' process whereby the Roman Catholic Church made its liturgy more accessible to worshippers but it was a much deeper process of discovery of the principles of worship which has affected both Catholics and Protestants.
Split into simpler sentences: The Liturgical Movement was called, in part, a'catching up' process whereby the Roman Catholic Church made its liturgy more accessible to worshippers. It was however a much deeper process of discovery of the principles of worship which has affected both Catholics and Protestants.