If you're asking what the purpose of the afterlife is, its a pretty complicated answer. The Afterlife has very different meaning and descriptions in many different cultures and beliefs. One thing always stays the same throughout though, its a place where people go after they die.
"The Afterlife (also referred to as life after death, the world to come, rebirth or reincarnation) is an existence in which the essential part of an individual's identity or their stream of consciousness continues to live after the death of their physical body."
What does the phrase “because I was not” emphasize about the speaker? The speaker is lonely and distanced from the rest of society, which is why he did not speak out. The speaker is deeply sorry and wants to justify why he did not speak out against the arrests.