Heaven's Gate members believed that the planet Earth was about to be recycled (wiped clean, renewed, refurbished and rejuvenated), and that the only chance to survive was to leave it immediately. While the group was formally against suicide, they defined "suicide" in their own context to mean "to turn against the Next Level when it is being offered," and believed that their "human" bodies were only vessels meant to help them on their journey. In conversation, when referring to a person or a person's body, they routinely used the word "vehicle"; when shown a picture of his son in an interview, Rio Di Angelo commented, "Look, there's the little vehicle."
The group believed in several paths for a person to leave the Earth and survive before the "recycling," one of which was hating this world strongly enough: "It is also possible that part of our test of faith is our hating this world, even our flesh body, to the extent to be willing to leave it without any proof of the Next Level's existence."
The members of the group added "-ody" to the first names they adopted in lieu of their original given names, which defines "children of the Next Level." This is mentioned in Applewhite's final video, "Do's Final Exit," that was filmed on March 19–20, 1997, just days prior to the suicides.
They believed "to be eligible for membership in the Next Level, humans would have to shed every attachment to the planet." (Balch, 2002, p. 211) This meant that all members had to give up all human-like characteristics such as their family, friends, sexuality, individuality, jobs, money and possessions (Balch, 2002, p. 211).
These basic beliefs of the cult stayed generally consistent over the years however, "the details of their ideology were flexible enough to undergo modification over time." (Lewis, 2001, p. 16) There are many examples of the cult adding or slightly changing their beliefs over the years. This includes modifying the way one can enter the Next Level, changing the way they describe themselves, placing more importance on the idea of Satan, and adding several other New Age concepts. One of these concepts was the belief of extraterrestrial walk-ins. When the cult began, "Applewhite and Nettles taught their followers that they were extraterrestrial beings. However, after the notion of walk-ins became popular within the New Age subculture, the Two changed their tune and began describing themselves as extraterrestrial walk-ins." (Lewis, 2001, p. 16) The idea of walk-ins is very similar to the concept of being possessed by spirits. A walk-in can be defined as "an entity who occupies a body that has been vacated by its original soul." (Lewis, 2001, p. 368) An extraterrestrial walk-in, which is what Heaven's Gate came to believe, is "a walk-in that is supposedly from another planet." (Lewis, 2001, p. 368) The concept of walk-ins actually aided Applewhite and Nettles in starting from a clean slate personally. They no longer were the people they had been prior to the start of the group, but had taken on a new life and this idea actually gave them a way to "erase their human personal histories as the histories of souls who formerly occupied the bodies of Applewhite and Nettles." (Lewis, 2001, p. 368)
Another New Age belief that Applewhite and Nettles adopted was the ancient astronaut hypothesis. The term "ancient astronauts" is used to refer to various forms of the concept that ufonauts visited our planet in the distant past. (Lewis, 2001, p. 16) Applewhite and Nettles took part of this concept and taught it as the belief that "aliens planted the seeds of current humanity millions of years ago, and have to come to reap the harvest of their work in the form of spiritual evolved individuals who will join the ranks of flying saucer crews. Only a select few members of humanity will be chosen to advance to this transhuman state. The rest will be left to wallow in the spiritually poisoned atmosphere of a corrupt world." (Lewis, 2001, p. 17) Only the individuals that chose to join Heaven's Gate and follow Applewhite and Nettle's belief and make the sacrifices that membership required would be allowed to escape human suffering.