The 2002 editio typica of the Missale Romanum contains the following Collect for the memorial of Saint Louis-Marie Grignion de Montfort, Priest. The Collect is an admirable synthesis of the charism of Saint Louis-Marie. Every line of the text alludes to an element characteristic of his spirituality. The English translation is my own.
O God, who willed to guide the steps
of your priest, saint Louis-Marie,
into the way of salvation and of delight in Christ
in the company of the Blessed Virgin,
grant that we, by following his example,
may meditate the mysteries of your love
and devote ourselves tirelessly to the upbuilding of your Church.