I came across this beautiful prayer a few days ago and it has stayed with me ever since. It is at the same time deeply charitable in its concern for the forgotten and a unsettling reminder that we, too, will someday drift out of living memory:
Prayer for the Forgotten Dead
O merciful God, take pity on those souls who have no particular friends and intercessors to recommend them to Thee, who, either through the negligence of those who are alive, or through length of time are forgotten by their friends and by all. Spare them, O Lord, and remember Thine own mercy, when others forget to appeal to it. Let not the souls which Thou hast created be parted from thee, their Creator.
May the souls of all the faithful departed, through the mercy of God, rest in peace.