Taken from goodshepherdcatechesis.com:
Montessori and the Origins of the Atrium
The Catechesis of the Good Shepherd was inspired by Maria Montessori's pioneering work in the field of education and her observations concerning the developmental and spiritual needs and capacities of the child. Montessori was already famous worldwide for developing her startling educational methods, through her work with developmentally delayed and underprivileged children, when she attended the Eucharistic Congress of 1905. There she was inspired by the vision of Pope Pius X who expressed the wish that children should participate in the Eucharist at an earlier age; eventually he issued the decree Quam Singular on August 8, 1910, which specified the age at which children are to be admitted to first communion. Montessori, a devout Roman Catholic, took that vision to heart and began creating materials to help children become more familiar with the mass. At the invitation of a community of Vincentian priests, she opened the first atrium in 1915 in Barcelona, Spain. She continued to develop materials on the Mass for children until she died in 1952.
Maria Montessori, M.D.
Message to Catholic Teachers On the eve of her death,
Dr. Maria Montessori sent this message to Catholic teachers gathered at a meeting in London, England.
"Never, as in this moment, has the Christian faith needed the sincere effort of those who profess it. I would like to ask all of you, who are gathered in this meeting, to consider the great help that children can bring to the defense of our faith.
Children come to us as a rain of souls, as a richness and a promise which can always be fulfilled but which needs the help of our efforts for its fulfillment.
Do not consider the child a weakling: the child is the builder of the human personality. That this personality be Christian or not depends on the environment around him and on those who guide his religious formation.
Do not think that because the child cannot understand in the same way that we adults understand that it is useless to allow him to participate in our religious practices.
The staunchest and deepest faith is generally found among the unsophisticated people whose women take their children to church while they are still breastfed: the child's unconscious absorbs divine powers while the conscious reasoning of adults is only human.
You who enjoy the great gift of belonging to the Catholic faith must intensely feel the great responsibility you have for future generations because, among you, there are those who have renounced the world to bring the world to God.
Take then, as help in your task, with faith and humility, "the all-powerful children" (Benedict XV). Take as your special task to watch that their limpid light be not dimmed. Protect in their development those natural energies implanted in the souls of children by the guiding hand of God. May God be with you at this meeting, and may He guide you in your conclusions and decisions."