Sikhs do not believe in an afterlife in either Heaven or Hell. Sikhism teaches that the soul reincarnates when the body dies. Sikhs believe that good, or bad actions, in this life, determine the life form into which a soul takes rebirth.
At the time of death, demonic ego centered souls may be destined to suffer great agonies, and pain, in the dark underworld of Narak.
A soul, fortunate enough to achieve grace, overcomes ego by meditating on God. In Sikhism, the focus meditation is to remember the divine Enlightener by calling out the name "Waheguru", either silently or aloud. Such a soul may attain liberation from the cycle of reincarnation. The emancipated soul experiences salvation in Sachkhand, the realm of truth, it exists eternally as an entity of radiant light.
Bhagat Trilochan, an author of Guru Granth Sahib scripture writes on the subject of afterlife, that at the time of death the final thought determine how one reincarnates. The soul takes birth in accordance with that which the mind last remembers. Those who dwell on thoughts of riches, or worries about wealth are born again as serpents and snakes. Those who dwell on thoughts of carnal relations are born into brothels. Those who remember their sons and daughters are born as a pig to become a sow birthing a dozen or more piglets with each pregnancy. Those who dwell on thoughts of their home houses or mansions, take the form of a ghostly goblin type specter haunting houses remembered. Those whose final thoughts are of the divine, merge eternally with the Lord of the Universe to dwell forever in the abode of radiant light.
"Ant kaal jo lachhamee simarai aisee chintaa meh jae marai ||
At the final moment, whom so ever remembers wealth, and dies with such thoughts...
Sarap jon val val aoutarai ||1||
is reincarnated as the serpent species over and over again. ||1||
Aree baa-ee gobid naam mat beesarai || rehaao ||
O sister, do not ever forget the Name of the Universal Lord. ||Pause||
Ant kaal jo istree simarai aisee chintaa meh jae marai ||
At the final moment, whom so ever remembers relations with women and dies with such thoughts...
Baesavaa jon val val aoutarai ||2||
is reincarnated as a courtesan over and over again. ||2||
Ant kaal jo larrikae simarai aisee chintaa meh jae marai ||
At the final moment, whom so ever remembers children, and dies with such thoughts...
Sookar jon val val aoutharai ||3||
is reincarnated as a swine over and over again. ||3||
Ant kaal jo mandar simarai aisee chinthaa meh jae marai ||
At the final moment, whom so ever remembers houses, and dies with such thoughts...
Praet jon val val aoutarai ||4||
is reincarnated as a ghost over and over again. ||4||
Ant kaal naaraa-in simarai aisee chintaa meh jae marai ||
At the final moment, whom so ever remembers the Lord, and dies with such thoughts...
Badat Tilochan tae nar mukataa peetanbar vaa kae ridai basai ||5||2||
Saith Trilochan, that person is liberated and the yellow robed Lord abides in that one's heart." ||5||2|| SGGS||526