All Saints Day dates back to Pope Gregory III (731-741). He set aside the first day in November to commemorate all the unknown martyrs and unknown saints now at rest with God. The feast is celebrated across many Christian Churches. In some places it is known as All Hallows (or All Holy Ones) and the evening before All Hallows is called Halloween.
All Saints Day is a celebration of our own loved ones who taught us the way of Jesus Christ through their love and example. It is a day to give thanks to God for the grace and goodness that they passed on to us.
All Saints Day is also a day to think of all the holy ones around the world who selflessly help others and live good lives and gave themselves back to God.
Finally, All Saints Day is a day to reflect on our own call to sanctity: not to be pious plaster cast saints, but to carry the hope and peace of Christ in our daily living. We reflect on the life and death of the holy ones, and on our own life and death, and our communion with the Divine Mystery.
Karl Rahner meditates on All Saints Day in the following words: “through God’s grace our life becomes, more and more, a life of faith…. all our memories and all our prayers are only the echo of the words of love that the holy living, in the silence of their eternity, softly and gently speak to our heart.”