The faithful on earth can assist these souls in purgatory in attaining the beatific vision through their prayers, good works and the offering of Mass.
In the early days of the Church, the names of the faithful departed were posted in Church so that the community would remember them in prayer. In the sixth century, the Benedictine monasteries held a solemn commemoration of deceased members at Whitsuntide, the days following Pentecost. In Spain, St. Isidore (d. 636) attested to a celebration on the Saturday before Sexagesima Sunday (the second Sunday before Lent, the eighth before Easter, in the old calendar). In Germany, Widukind, Abbot of Corvey (d. 980) recorded a special ceremony for the faithful departed on Oct. 1. St. Odilo, the Abbot of Cluny (d. 1048), decreed for all of the Cluniac monasteries that special prayers be offered and the Office of the Dead sung for all of the souls in purgatory on Nov. 2, the day after All Saints. The Benedictines and Carthusians adopted that same devotion, and soon Nov. 2 was adopted as the Feast of All Souls for the whole Church.
Other customs have arisen over time in the celebration of All Souls Day. The Dominicans in the 15th century instituted a custom of each priest offering three Masses on the Feast of All Souls. Pope Benedict XIV in 1748 approved this practice, and it rapidly spread throughout Spain, Portugal and Latin America. During World War I, Pope Benedict XV, recognizing the number of war dead and the numerous Masses that could not be fulfilled because of destroyed Churches, granted all priests the privilege of offering three Masses on All Souls Day: one for the particular intention, one for all of the faithful departed and one for the intentions of the Holy Father.
Other customs have developed regarding All Souls. In Mexico, relatives make garlands, wreathes and crosses of real and paper flowers of every color to place on the graves of deceased relatives the morning of All Souls. The family will spend the entire day at the cemetery. The pastor will visit the cemetery, preach and offer prayers for the dead, and then bless the individual graves. “Skeleton” candy is given to the children.
Similar practices occur in Louisiana. The relatives whitewash and clean the tombstones, and prepare garlands, wreathes and crosses of real and paper flowers to decorate them. In the afternoon of All Saints, the priest processes around the cemetery, blessing the graves and reciting the rosary. Candles are lit near the graves at dusk, one for each deceased member. On All Souls day, Mass is usually offered at the cemetery.
In the Middle Ages, superstitious belief, probably influenced from Celtic paganism, held that the souls in purgatory appeared on All Souls Day as witches, toads, goblins, etc., to persons who committed wrongs against them during their lives on earth. For this reason, some ethnic groups also prepared food offerings to feed and to appease the spirits on this day. These practices are probably remnants of the Celtic Samhain festivities.
Nevertheless, All Souls Day as well as all Saints Day are rooted in Christian belief and arose in this life of the Church through a healthy spirituality, despite some pagan trappings that may have survived and have remained attached to their celebration.