What All Souls, the Commemoration of the Faithful Departed is all about, why, regardless of some people's current denigration of the practice, we pray for the dead:
From Papa's Angelus Message on All Souls' Day.
Christian hope is never something merely individual, it is always a hope for others. Our lives are deeply linked to one another, and the good and bad each of us does always touches other people. The prayer of a pilgrim soul in the world can help another soul that continues purifying itself after death. This is why today the Church invites us to pray for our deceased loved ones and to spend time at their tombs in cemeteries.
I loved that quote I learned recetnly, Blessed Carl of Austria to his wife on the occasion of their marriage, something like-- well, now we must help each other to get to Heaven.