Ad maiorem Dei gloriam or ad majorem Dei gloriam, also rendered as the abbreviation AMDG, is the Latin motto of the Society of Jesus (Jesuits), a religious order of the Catholic Church. It means "For the greater glory of God".
Ad maiorem Dei gloriam Wikipedia
The origin of the phrase is attributed to the founder of the Jesuits, Saint Ignatius of Loyola , who intended it to serve as a cornerstone sentiment of the society's religious philosophy. The full phrase attributed to St. Ignatius is Ad maiorem Dei gloriam inque hominum salutem or "for the greater glory of God and the salvation of humanity." It is a summary of the idea that any work that is not evil, even one that would normally be considered inconsequential to the spiritual life, can be spiritually meritorious if it is performed in order to give glory to God.
A common Jesuit emblem depicts the mottos surrounding the initials IHS. IHS is a Greek monogram composed by three letters (iota, eta and sigma) for the name of Jesus Christ used since the 3rd century as an abbreviation. "St. Ignatius of Loyola adopted the monogram in his seal as general of the Society of Jesus (1541), and thus it became the emblem of his institute. IHS was sometimes wrongly understood as 'Jesus Hominum (or Hierosolymae) Salvator', i.e. Jesus, the Saviour of men (or of Jerusalem=Hierosolyma)."
When images of Saint Ignatius depict him carrying a book, the motto is often inscribed within—representative of the religious writings of the saint.
This phrase is the motto of many Jesuit educational institutions, including eight of the twenty-eight members of the Association of Jesuit Colleges and Universities, and many high schools worldwide. In Georgetown University's Gaston Hall, the phrase is followed by inque hominum salutem, producing a longer phrase: "For the greater glory of God and the salvation of humanity." Typical of the buildings of many Jesuit institutions, the cornerstones of those on Fordham University's campus bear the inscribed abbreviation “AMDG”, and the school's University Church hosts the 2,776-pipe “Maior Dei Gloria” organ, which derives its name from the motto.
It once was common for students at Jesuit schools and universities to write the initials at the tops of their pages, to remind them that even their schoolwork ought to be dedicated to the glory of God. The abbreviation was frequently included in the signatures of Pope John Paul II.
The motto of the Catholic fraternity Alpha Delta Gamma is Ad Dei Gloriam, which translates to "For the Glory of God." This motto is the origin of fraternity's name, as the Roman initials "ADG" are rendered in Greek with the letters alpha, delta, and gamma.
It is repeatedly quoted by the Jesuit character in Flann O'Brien's book The Hard Life. Sir Edward Elgar used it as the dedication of his setting of Cardinal Newman's poem The Dream of Gerontius. In 1939, Benjamin Britten wrote a choral piece A.M.D.G. (Ad Majorem Dei Gloriam) of seven settings of Gerard Manley Hopkins.