The Church is "the pillar and bulwark of truth" (1 Tm 3:15). Jesus Himself founded the Church to be His body (e.g. Eph 1:22-23), and He gave her the keys of the kingdom of heaven (Mt 16:19). Therefore, the universal Church will always faithfully proclaim the Lord's will and always rightly interpret His word.
For two thousand years, the Church throughout the world has authoritatively taught that we should pray for our brothers and sisters in purgatory so that they will be purified as soon as possible and enter heaven. The Church teaches in the Catechism: "From the beginning the Church has honored the memory of the dead and offered prayers in suffrage for them, above all the Eucharistic sacrifice, so that, thus purified, they may attain the beatific vision of God" (1032). "Our prayer for them is capable not only of helping them, but also of making their intercession for us effective" (Catechism, 958).
Because of the teaching of the Church, we can be sure that it is "very excellent and noble" to pray for the dead (2 Mc 12:43). Therefore, let us pray for the dead not only today but every day and even throughout each day. As we pray, some of our dead brothers and sisters are entering heaven, and we are being graced through their prayers. "Eternal rest grant unto them, O Lord, and let perpetual light shine upon them. May their souls and the souls of all the faithful departed through the mercy of God rest in peace. Amen."