Afterlife
Afterlife was a term referring to any kind of continued existence after one's death. Many different beliefs existed among the different cultures.

Beliefs 
Ferengi tradition told that all life profit and loss statements were weighted. Worthy traders were sent to the Divine Treasury, the others to the Vault of Eternal Destitution. ()

Lurians  brought gifts of food and drink for the deceased so they will have something to sustain them in the afterlife. ()

Some Humans believed that a person would be sent to a different afterlife, either Heaven or Hell, depending on their actions in life. A third related location was Purgatory. (; ) In 2365, Captain Picard explained that there were two contemporary philosophies on death. One was the belief that death was the transformation into an indestructible and unchanging form. The purpose of the entire universe was to then maintain that form in a Garden of Eden-like place. The other was that death was simply blinking into nothingness. Picard himself believed that the existence of lifeforms was part of a reality beyond what was currently understood as reality and therefore both philosophies were insufficient. ()Considering the marvelous complexity of the universe, its... clockwork perfection, its balances of this against that, matter, energy, gravitation, time, dimension - I believe that our existence must be more than either of these philosophies. That what we are goes beyond Euclidean or other practical measuring systems, and that our existence is part of a reality beyond what we understand now as reality. -- Capt. Jean-Luc PicardMany cultures believed that people would exist in the afterlife in a "pure" physical state, cured of health issues from their previous life. In 2368, when Geordi La Forge and Ro Laren were thrown out of phase by a transporter accident and declared dead by a crew that could not see them, the blind La Forge regarded the continued function of his VISOR as proof that, contrary to what Ro believed, they were still alive. () 

Klingon mythology taught that honorable warriors were sent to Sto-vo-kor when they die, while dishonorable ones were sent to Gre'thor. ()

Talaxians mythology had a belief in an afterlife known as the Great Forest, in which a great tree stood at the center. It was said that upon death, a Talaxian went to the afterlife and met the souls of their deceased family upon arrival. ()

The Vhnori, when near death, were placed in a coffin-like device that euthanized the occupant. They believed that after this they then transported them to the "Next Emanation". ()

In Akaali mythology, the afterlife was referred to as the afterworld, and said to be ruled by Draylan. ()

The Vori believed in the Gloried Way After. ()

Drayans believed that the energy in a person was set free at the time of death. ()

Some Arretans believed in oblivion after death. Thalassa told her husband that oblivion with him didn't frighten her. ()

Vulcans believed in the katra. Tuvok said that Vulcans believed a person's katra, or what some may call a soul, survived after death. Although he believed in it without question as a child, he recently experienced doubts. ()

The Borg have no concept of an afterlife. However, the consciousness of individual survived as part of the Collective.()

Appearances
In 2369, after the failure of his artificial heart, Picard seemed to experience going to the afterlife run by Q as God. ()

A species of non-corporeal life forms who fed on the consciousness of corporeal beings used a Matrix to trap the minds of people close to  death. The aliens needed the people to enter voluntarily, so they claimed that the Matrix was the afterlife. () One such alien appeared to Janeway and claimed to be her father. 

B'Elanna Torres experienced being sent to Gre'thor to save her mother Miral from dishonor. ()

When Neelix died and didn't see anything, he felt so distressed that he thought of taking his own life. (). Someone does have a dream about the Great Forest, however. 

Quark had a dream about going to the Divine Treasury.  

In 2375, Julian Bashir and Miles O'Brien were near death while exploring the mind of Luther Sloan. Seeing a light appear in a certain corridor, O'Brien suggested it was The Great Beyond. ()

See also
 Ghost
God
Religion

External link

de:Jenseits
Mythology
Death