There are many holy souls in Purgatory that need help. Purgatory, according to some saints, is just as painful as hell. Devotion to the holy souls, that is, praying for them, is very beneficial to both the souls and you. The souls will pray for you, and you will have an eternally grateful benefactor. St. Augustine once said that he would feel that his salvation was guaranteed if he only had one soul. Prayers will shorten their time and earn their gratitude, but the most effective is the Mass. If all truly knew the power of the Mass, it is likely that mass intentions would be booked fifty years into the future at every parish. The Mass is infinately worth more than one billion prayers, because in it, Jesus renews the sacrifice of His Body and His Blood. The holy souls have granted many favors to those that prayed for them. They once helped a duke to win a battle; They once saved a soldier's life; They once appeared to a man and told him that he was to die soon, so that he could make a condession. Many cases have proven that the holy souls are grateful to those who pray for them, and they will pray for you much more than you would normally pray, because they are in heaven and you are not. Their intercession is not to be taken lightly. So, start a devotion for the holy souls now. Maybe say a Hail Mary whenever you pass by a cemetery, or a decade of the Rosary every night. And do not forget, one day you will be in Purgatory and needing prayers too!