At times, G-d chose to use the harsh reality of life in the desert near the Promised Land as a practical teaching tool to mold and shape His people. The Essenes went willingly into this wasteland to allow Him to do just that: to teach them His words and how to walk obediently in His ways.
The Essenes clustered in secluded communities that, generally at least in matters of scripture, excluded women. Property was used to the benifit all the community and all details of daily life revolved around G-d. The Essenes were never numerous; Pliny fixed their number at some 4,000 in his day.
Like the Pharisees, the Essenes meticulously observed the mitzvos found in Torah (excluding most of the oral law), the sabbath, and ritual purity. They also professed belief in immortality and divine punishment for sin. But, unlike the Pharisees, the Essenes denied the resurrection of the physical body and refused to immerse themselves in public life. With few exceptions, they shunned Temple worship and were content to live asectic lives of manual labour in seclusion. The sabbath was reserved for day-long prayer and meditation on the Torah. Oaths were frowned upon, but once taken they could not be recinded (even marriage vows).
After a year’s probation, proselytes received their Essenian emblems but could not participate in common meals for two more years. Those who qualified for membership were called upon to swear piety to G-d, justice toward men, hatred of falsehood, love of truth, and faithful observance of all other tenets of the Essene sect which had to be supported with at least 3 indecent sources in the Tanahk. Thereafter new converts were allowed to take their noon and evening meals in silence with the others.
Flavius Josephus: translation and commentary, vol. 1b: Judean War (Leiden: Brill, 2008).
The Jewish War, Book II, Chapter 8
(8.2)
119 For three forms of philosophy are pursued among the Judeans: the members of one are Pharisees, of another Sadducees, and the third [school], who certainly are reputed to cultivate seriousness, are called Essenes; although Judeans by ancestry, they are even more mutually affectionate than the others. 120 Whereas these men shun the pleasures as vice, they consider self-control and not succumbing to the passions virtue. And although there is among them a disdain for marriage, adopting the children of outsiders while they are still malleable enough for the lessons they regard them as family and instill in them their principles of character: 121 without doing away with marriage or the succession resulting from it, they nevertheless protect themselves from the wanton ways of women, having been persuaded that none of them preserves her faithfulness to one man.
(8.3)
122 Since [they are] despisers of wealth—their communal stock is astonishing—, one cannot find a person among them who has more in terms of possessions. For by a law, those coming into the school must yield up their funds to the order, with the result that in all [their ranks] neither the humiliation of poverty nor the superiority of wealth is detectable, but the assets of each one have been mixed in together, as if they were brothers, to create one fund for all. 123 They consider olive oil a stain, and should anyone be accidentally smeared with it he scrubs his body, for they make it a point of honor to remain hard and dry, and to wear white always. Hand-elected are the curators of the communal affairs, and indivisible are they, each and every one, [in pursuing] their functions to the advantage of all.
(8.4)
124 No one city is theirs, but they settle amply in each. And for those school-members who arrive from elsewhere, all that the community has is laid out for them in the same way as if they were their own things, and they go in and stay with those they have never even seen before as if they were the most intimate friends. 125 For this reason they make trips without carrying any baggage at all—though armed on account of the bandits. In each city a steward of the order appointed specially for the visitors is designated quartermaster for clothing and the other amenities. 126 Dress and also deportment of body: like children being educated with fear. They replace neither clothes nor footwear until the old set is ripped all over or worn through with age. 127 Among themselves, they neither shop for nor sell anything; but each one, after giving the things that he has to the one in need, takes in exchange anything useful that the other has. And even without this reciprocal giving, the transfer to them [of goods] from whomever they wish is unimpeded.
(8.5)
128 Toward the Deity, at least: pious observances uniquely [expressed]. Before the sun rises, they utter nothing of the mundane things, but only certain ancestral prayers to him, as if begging him to come up. 129 After these things, they are dismissed by the curators to the various crafts that they have each come to know, and after they have worked strenuously until the fifth hour they are again assembled in one area, where they belt on linen covers and wash their bodies in frigid water. After this purification they gather in a private hall, into which none of those who hold different views may enter: now pure themselves, they approach the dining room as if it were some [kind of] sanctuary. 130 After they have seated themselves in silence, the baker serves the loaves in order, whereas the cook serves each person one dish of one food. 131 The priest offers a prayer before the food, and it is forbidden to taste anything before the prayer; when he has had his breakfast he offers another concluding prayer. While starting and also while finishing, then, they honor God as the sponsor of life. At that, laying aside their clothes as if they were holy, they apply themselves to their labors again until evening. 132 They dine in a similar way: when they have returned, they sit down with the vistors, if any happen to be present with them, and neither yelling nor disorder pollutes the house at any time, but they yield conversation to one another in order. 133 And to those from outside, the silence of those inside appears as a kind of shiver-inducing mystery. The reason for this is their continuous sobriety and the rationing of food and drink among them—to the point of fullness.
(8.6)
134 As for other areas: although there is nothing that they do without the curators’ having ordered it, these two things are matters of personal prerogative among them: [rendering] assistance and mercy. For helping those who are worthy, whenever they might need it, and also extending food to those who are in want are indeed left up to the individual; but in the case of the relatives, such distribution is not allowed to be done without [permission from] the managers. 135 Of anger, just controllers; as for temper, able to contain it; of fidelity, masters; of peace, servants. And whereas everything spoken by them is more forceful than an oath, swearing itself they avoid, considering it worse than the false oath; for they declare to be already degraded one who is unworthy of belief without G-d. 136 They are extraordinarily keen about the compositions of the ancients, selecting especially those [oriented] toward the benefit of soul and body. On the basis of these and for the treatment of diseases, roots, apotropaic materials, and the special properties of stones are investigated.
(8.7)
137 To those who are eager for their school, the entry-way is not a direct one, but they prescribe a regimen for the person who remains outside for a year, giving him a little hatchet as well as the aforementioned waist-covering and white clothing. 138 Whenever he should give proof of his self-control during this period, he approaches nearer to the regimen and indeed shares in the purer waters for purification, though he is not yet received into the functions of communal life. For after this demonstration of endurance, the character is tested for two further years, and after he has thus been shown worthy he is reckoned into the group. 139 Before he may touch the communal food, however, he swears dreadful oaths to them: first, that he will observe piety toward the deity; then, that he will maintain just actions toward humanity; that he will harm no one, whether by his own deliberation or under order; that he will hate the unjust and contend together with the just; 140 that he will always maintain faithfulness to all, especially to those in control, for without G-d it does not fall to anyone to hold office, and that, should he hold office, he will never abuse his authority—outshining his subordinates, whether by dress or by some form of extravagant appearance; 141 always to love the truth and expose the liars; that he will keep his hands pure from theft and his soul from unholy gain; that he will neither conceal anything from the school-members nor disclose anything of theirs to others, even if one should apply force to the point of death. 142 In addition to these, he swears that he will impart the precepts to no one otherwise than as he received them, that he will keep away from banditry, and that he will preserve intact their school’s books and the names of the angels. With such oaths as these they completely secure those who join them.
(8.8)
143 Those they have convicted of sufficiently serious errors they expel from the order. And the one who has been reckoned out often perishes by a most pitiable fate. For, constrained by the oaths and customs, he is unable to partake of food from others. Eating grass and in hunger, his body wastes away and perishes. 144 That is why they have actually shown mercy and taken back many in their final gasps, regarding as sufficient for their errors this ordeal to the point of death.
(8.9)
145 Now with respect to trials, [they are] just and extremely precise: they render judgment after having assembled no fewer than a hundred, and something that has been determined by them is non-negotiable. There is a great reverence among them for—next to G-d—the name of the lawgiver, and if anyone insults him he is punished by death. 146 They make it point of honor to submit to the elders and to a majority. So if ten were seated together, one person would not speak if the nine were unwilling. 147 They guard against spitting into [their] middles or to the right side and against applying themselves to labors on the seventh days, even more than all other Judeans: for not only do they prepare their own food one day before, so that they might not kindle a fire on that day, but they do not even dare to transport a container—or go to relieve themselves. 148 On the other days they dig a hole of a foot’s depth with a trowel—this is what that small hatchet given by them to the neophytes is for—and wrapping their cloak around them completely, so as not to outrage the rays of G-d, they relieve themselves into it [the hole]. 149 After that, they haul back the excavated earth into the hole. (When they do this, they pick out for themselves the more deserted spots.) Even though the secretion of excrement is certainly a natural function, it is customary to wash themselves off after it as if they have become polluted.
(8.10)
150 They are divided into four classes, according to their duration in the training, and the later-joiners are so inferior to the earlier-joiners that if they should touch them, the latter wash themselves off as if they have mingled with a foreigner. 151 [They are] long-lived, most of them passing 100 years—as a result, it seems to me at least, of the simplicity of their regimen and their orderliness. Despisers of terrors, triumphing over agonies by their wills, considering death—if it arrives with glory—better than deathlessness. 152 The war against the Romans proved their souls in every way: during it, while being twisted and also bent, burned and also broken, and passing through all the torture-chamber instruments, with the aim that they might insult the lawgiver or eat something not customary, they did not put up with suffering either one: not once gratifying those who were tormenting [them], or crying. 153 But smiling in their agonies and making fun of those who were inflicting the tortures, they would cheerfully dismiss their souls, [knowing] that they would get them back again.
(8.11)
154 For the view has become tenaciously held among them that whereas our bodies are perishable and their matter impermanent, our souls endure forever, deathless: they get entangled, having emanated from the most refined ether, as if drawn down by a certain charm into the prisons that are bodies. 155 But when they are released from the restraints of the flesh, as if freed from a long period of slavery, then they rejoice and are carried upwards in suspension. For the good, on the one hand, sharing the view of the sons of Greece they portray the lifestyle reserved beyond Oceanus and a place burdened by neither rain nor snow nor heat, but which a continually blowing mild west wind from Oceanus refreshes. For the base, on the other hand, they separate off a murky, stormy recess filled with unending retributions. 156 It was according to the same notion that the Greeks appear to me to have laid on the Islands of the Blessed for their most courageous men, whom they call heroes and demi-gods, and for the souls of the worthless the region of the impious in Hades, in which connection they tell tales about the punishments of certain men—Sisyphuses and Tantaluses, Ixions and Tityuses—establishing in the first place the [notion of] eternal souls and, on that basis, persuasion toward virtue and dissuasion from vice. 157 For the good become even better in the hope of a reward also after death, whereas the impulses of the bad are impeded by anxiety, as they expect that even if they escape detection while living, after their demise they will be subject to deathless retribution. 158 These matters, then, the Essenes theologize with respect to the soul, laying down an irresistible bait for those who have once tasted of their wisdom.
(8.12)
159 There are also among them those who profess to foretell what is to come, being thoroughly trained in holy books, various purifications, and concise sayings of prophets. Rarely if ever do they fail in their predictions.
(8.13)
160 There is also a different order of Essenes. Though agreeing with the others about regimen and customs and legal matters, it has separated in its opinion about marriage. For they hold that those who do not marry cut off the greatest part of life, the succession, and more: if all were to think the same way, the line would very quickly die out. 161 To be sure, testing the brides in a three-year interval, once they have been purified three times as a test of their being able to bear children, they take them in this manner; but they do not continue having intercourse with those who are pregnant, demonstrating that the need for marrying is not because of pleasure, but for children. Baths [are taken] by the women wrapping clothes around themselves, just as by the men in a waist-covering. Such are the customs of this order.
I'm giving a Wednesday Mens bible study on The Essene right now there's a few documentaries out there that are very well and fall betweenJosephus' writings and Pliny the Elders writings on the Essene.
EDIT: It is my beleif the John the Emercer and Barnabas were Essene. Many of Essene teachings fall in line with what Yeshua taught.