These individuals study End Times prophecy and believe that one of various scenarios might occur in their lifetime. While some Christians (and even people of other religions) believe that the Rapture will follow a period of Tribulation, others believe that the Rapture is imminent and will precede the Tribulation ("Pre-Trib Rapture"). There is a wide range of beliefs and attitudes in this group. They run the gamut from pacifist to armed camp, and from having no food stockpiles (leaving their sustenance up to God's providence) to storing decades' worth of food.
With goTenna you use a simple smartphone messaging app as a platform for sending SOS messages along with your handheld hunting GPS coordinates should you need emergency help. You can also use it to chat with emergency services so they know your exact condition and can prepare accordingly. It’s off-grid survival gear at its best and could be the difference between life and death.
One newsletter deemed by some to be one of the most important on survivalism and survivalist retreats in the 1970s was the Personal Survival ("P.S.") Letter (circa 1977–1982). Published by Mel Tappan, who also authored the books Survival Guns and Tappan on Survival. The newsletter included columns from Tappan himself as well as notable survivalists such as Jeff Cooper, Al J Venter, Bruce D. Clayton, Nancy Mack Tappan, J.B. Wood (author of several gunsmithing books), Karl Hess, Janet Groene (travel author), Dean Ing, Reginald Bretnor, and C.G. Cobb (author of Bad Times Primer). The majority of the newsletter revolved around selecting, constructing, and logistically equipping survival retreats. Following Tappan's death in 1980, Karl Hess took over publishing the newsletter, eventually renaming it Survival Tomorrow.
Each type you listed (save a couple) will have its uses in a community (group if you will), generally having a small trusted group with each having several skills in the various fields (prepper, homesteader, and survivalist) I believe would be an effective team, though as each group works together would it not be best to ensure that each has overlapping skills in case of injury, death, or other reasoning they can not fulfill their duties?
The increased inflation rate in the 1960s, the US monetary devaluation, the continued concern over a possible nuclear exchange between the US and the Soviet Union, and perceived increasing vulnerability of urban centers to supply shortages and other systems failures caused a number of primarily conservative and libertarian thinkers to promote individual preparations. Harry Browne began offering seminars on how to survive a monetary collapse in 1967, with Don Stephens (an architect) providing input on how to build and equip a remote survival retreat. He gave a copy of his original Retreater's Bibliography to each seminar participant.
Another concern when you’re lost in the wild is where to procure potable water. Sometimes there will be bubbling streams of crystal clear water rolling down wooded hillsides to fill your water bottle and sometimes you’ll have little more than a stagnant pool standing between you and dehydration. The LifeStraw Personal Water Filter is survival gear that can turn that stagnant pool into a lifesaver.