The object of the Legion of Mary is the glory of God through the holiness of its members developed by prayer and active co-operation, under ecclesiastical guidance, in Mary's and the Church's work of crushing the head of the serpent and advancing the reign of Christ.
The spirit of the Legion of Mary is that of Mary herself. Especially does the Legion aspire after her profound humility, her perfect obedience, her angelical sweetness, her continual prayer, her universal mortification, her altogether spotless purity, her heroic patience, her heavenly wisdom, her self-sacrificing courageous love of God, and above all her faith, that virtue which has in her alone been found in its utmost extent and never equalled. Inspired by this love and faith of Mary, her Legion essays any and every work and "complains not of impossibility, because it conceives that it may and can do all things." (Imitation of Christ, Book 3:5)