Conversation so far:
where does the idea of purgatory come from in the bible
Roman Catholic belief in after-life purification is based on the practice of praying for the dead, which is mentioned in 2 Maccabees 12:42-44, part of Sacred Scripture.
when was the practice of praying for the dead first adopted
According to the Catechism of the Catholic Church praying for the dead was adopted by Christians from the beginning.

Question: what is the purpose of the practice
Self-contained rewrite: what is the purpose of the practice of praying for the dead