Why has the Church appointed this feast?
To honor God in His saints, in whom He has shown Himself so wonderful, and to thank Him, as the author of all sanctity, for the benefits He has bestowed upon them.
To put us in lively remembrance of the communion of saints; that is, of all true children of the Church, whether they belong to the Church militant on earth, to the Church suffering in purgatory, or to the Church triumphant in heaven; but more particularly to cause us to consider, with earnestness, the communion of the saints in heaven with us, who are yet combating on earth.
To encourage us to strive for the like sanctity with them, and to teach us that it is by no means impossible; for if thousands of men could become saints, why should not we, who can do all things through Him Who strengthens us, and has sent the Holy Ghost for our sanctification?
To pay honor to those saints to whom no particular day in the year is dedicated.
That, in consideration of so many intercessors, God may grant us perfect reconciliation, may give us a share in their merits, and may grant us the grace of one day sharing in their joy in heaven.
By whom was this feast instituted?
By Pope Boniface IV, who, in the year 610, appropriated the Pantheon (that is, the temple of all gods) to the divine service of Christians, dedicated it to the Blessed Virgin and an saints, and commanded this feast in honor of all saints to be celebrated at Rome every year. Gregory IV, in the year 840, extended this feast to the whole Church, and transferred it to the 1st of November.
O Almighty God, Who hast granted us to venerate in one, solemnity the merits of an Thy saints, we beseech Thee that, as our intercessors are multiplied, Thou wouldst bestow upon us the desired abundance of mercy. Through Christ our Lord, Amen.