This is a day of Obligation.
From the 1945 Marian Missal:
We can pay no greater honor to the Saints than by offering up to God in their name the Blood of Jesus. The efficacy of their past merits and present prayers is greatly increased when offered to God in close association with the merits and prayers of Our Lord. Therefore the Church commemorates on this day all the Saints in Heaven without exception, and thus honors also those who are unknown and who have no public recognition in the liturgy. The custom of keeping holy one day in the year as the festival of all God’s saints, whether commemorated in the Liturgy or not dates back to at least the beginning of the Fifth Century.
In ancient times it was usually called the feast of All Holy Martyrs. The day of its celebration varied; and in the East, even now, All Saints is in most places a movable feast. Pope St. Boniface IV, when dedicating the Roman Pantheon as the Church of Our Blessed Lady and All Holy Martyrs, appointed November I for the chief annual festival in the sacred building.
Pope Gregory III built an oratory at St. Peter’s in honor of all the saints, confessors as well as martyrs who had died in all parts of the world. Pope Gregory IV chose November 1st as the Feast of All Saints. The octave was added by Pope Sixtus IV.
On this day, the Church gives us an admirable vision of heaven in the Epistle. In addition to those whose names are known, Holy Mother Church recalls in a magnificent scene all the others, part of “a great multitude, which no man could number, of all nations and tribes standing before the throne and in sight of the Lamb, clothed with white robes, and palms in their hands,” (Apoc. 7:9) all proclaiming Him who redeemed them in His Blood.
The feast of All Saints is a call to us, and should inspire us with tremendous hope. Among the saints of heaven are some whom we have known. All lived on Earth lives similar to our own. They were baptized, marked with the sign of faith, were faithful to Christ’s teaching, and have gone before us to the heavenly home whence they call on us to follow them. The Gospel of the Beatitudes shows the road that they followed; there is no other that will lead us to the same final destination where:
“The glorious company of the apostles praise Thee.
The goodly fellowship of the prophets praise Thee.
The white-robed army of martyrs praise Thee.
All Thy saints and elect with one voice do acknowledge Thee,
O Blessed Trinity, one God!” (Te Deum, closing hymn of Matins)
|Omnípotens sempitérne Deus, qui nos ómnium sanctórum tuórum mérita sub una tribuísti celebritáte venerári: quæsumus, ut desiderátam nobis tuæ propitiatiónis abundántiam, multiplicátis intercessóribus largiáris. Per Dóminum nostrum Jesum Christum Fílium tuum, qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus, per omnia saecula saeculorum.
|Almighty and everlasting God, who hast granted to honor in one solemn Feast the merits of all Thy Saints: we beseech Thee, that since so many are praying for us, Thou wouldst pour forth upon us the abundance of Thy mercy, for which we long. Through our Lord Jesus Christ, Thy Son, Who liveth and reigneth with Thee in the unity of the Holy Ghost, God,
forever and ever.
|Múnera tibi Dómine, nostræ devotiónis offérimus: quæ et pro cunctórum tibi grata sint honóre justórum, et nobis salutária, te miseránte, reddántur. Per Dóminum nostrum Jesum Christum Fílium tuum, qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus,
Per omnia saecula saeculorum.
|We offer Thee, O Lord, the gifts of our devotion; that they be made pleasing to Thee for the honor of all the just and, by Thy mercy, be profitable to ourselves. Through our Lord Jesus Christ, Thy Son, Who liveth and reigneth with Thee in the unity of the Holy Ghost, God,
Forever and ever.
|Da quæsumus, Dómine, fidélibus pópulis ómnium Sanctòrum semper veneratióne lætári: et eórum perpétua supplicatióne muníri. Per Dóminum nostrum Jesum Christum Fílium tuum, qui tecum vivit et regnat in unitáte Spíritus Sancti, Deus,per omnia saecula saeculorum.||Grant to Thy faithful people, we beseech Thee, O Lord, ever to rejoice in the veneration of all Thy saints and to be defended by their unceasing prayers, Through our Lord Jesus Christ, Thy Son, Who liveth and reigneth with Thee in the unity of the Holy Ghost, God,
forever and ever.