I was watching this video of the beatification of Blessed John Paul II and I was struck by a thought while Pope Benedict XVI was kneeling in front of the coffin of the Blessed JPII in prayer. In pagan Rome, it was made lawful (and mandatory) that the emperor be declared a god to be worshipped. In Catholic Rome, JPII was declared to now be among those blessed to forever worship God and serve him day and night in His temple. Prayer to the Roman emperors is without effect, for they are not gods. Prayer to the saints in Heaven, those made righteous in Christ, have great effect, because they add their prayers to our intentions, praying to the one true God who is Father, Son and Holy Spirit.
There are many cultures that include some ancestor worship. As in many things that spring out of humanity, they might have caught some of the truth but in a corrupt form. In Christ, we get the truth: death is not the end, indeed, but there is only one God to worship, for a community of saints who are alive in Christ for all eternity, always united by love through the Holy Spirit.