And God called the firmament Heaven. And the evening and the morning were the second day. –Gen 1:8
Those who believe in heaven, especially those of the Judeo-Christian faith, generally hold that it (or Hell) is one of the two possible afterlife destinations all humans. In unusual instances, humans have had, according to many testimonies and traditions, personal knowledge of Heaven. They assert this is for the purpose of teaching the rest of humanity about life, Heaven, and God.
While there are abundant and varied sources for conceptions of Heaven, the typical believer's view appears to depend largely on his particular religious tradition. Various religions have described Heaven as being populated by angels, demons, gods and goddesses, and/or heroes (especially in Greek mythology). Heaven is generally thought of as a place of eternal happiness.
In old and new testament biblical religions, the belief in heaven appears to have supplanted the earlier concept of Sheol (mentioned in Isaiah 38:18, Psalms 6:5 and Job 7:7-10). Jewish converts to this concept of heaven and hell included the group known as the Pharisees. The larger, dogmatically conservative Sadducees maintained their belief in Sheol. While it was the Sadducees that represented the Jewish religious majority it was the Pharisees who best weathered Roman occupation, and their belief in Zoroaster's heaven and hell was passed on to both Christianity and Islam (in which heaven is referred to as Jannah (Arabic: جنّة), the Islamic conception of paradise).