Part I 

In the Nether Update, they changed random whimsical zombie pigmen into zombified piglins, and added piglins. They appear more imposing and less like normal pigs, with boar-like tusks. Most tellingly, they have whited-out eyes which are a single pixel, unlike all other Minecraft mobs before; Across media, whited-out eyes are used to symbolize demonic possession. In the Bible, Jesus cast the demon Legion out of a possessed woman, and allowed them to enter a herd of pigs, which they drowned in a lake. The Nether was originally called the Hell biome, and Hell is referred to as a lake of fire. Piglins are not as peaceful as zombie pigmen were, being much more hostile to players, but they idolize gold more than anything. King Solomon purchased the 72 demonic sigils for 666 talents of gold. Etymologically, piglin sounds like it derives its suffix from the ancient Hebrew word "lilin," which refers to desert spirits in Jewish and Mesopotamian folklore which attacked men in the night. They also eat the hoglins which were introduced at the same time, which appear to be lesser forms related to themselves. This reminds me of Saturn, who ate his children. Another thing about piglin that reminds me of Saturn is one variant of their bastions, which is almost a perfect black cube; and a black cube is one symbol of Saturn.

Part II

Netherite doesn't fit the prior tone of Minecraft and its armor, ascending in strength along with cheesy cheerful color. Instead, the Nether-based material is intimidating and blends into darkness. Its helm is shaped differently from all other armor, being cubic at the "north pole" of the body. Its chestplate is also shaped differently, encircled by a ring, along the body's "equator," or waist. The boots are shaped differently, pointing out to almost appear similar to an inverted pentagram(, which is an occult magickal symbol co-opted by satanic sects to dually represent Theleman Baphomet's goat head).

Netherite as a material itself is an alloy of gold and ancient debris, found in the Nether(/the "Hell" biome), which then is used to coat diamond. Mojang introduced a new block specifically for this mechanic of eclipsing bright diamond with black, and while many players found it to be tedious, superfluous, or just to have a confusing purpose, eclipses are a popular occult symbol/time for occult rituals. In addition to other magickal and witchcraft connections, if one looks at it from a Christian perspective, the Bible is thought by many to suggest that Jesus died on the cross during a solar eclipse.

Adamant is a material described in antiquity and the middle ages as being the material of the gods and the material that is used to chain demons in hell, respectively. It originally meant diamond, then something as strong as diamond, and finally, an ultimately hard mythical material. The medieval or early Renaissance epic Paradise Lost, which details a journey through hell, elaborates from earlier literature to claim that Satan and his army are not only bound in hell by adamantine chains, but that they wear adamantine armor, and that Lucifer wields adamantine weapons. Additionally, chains as an item were first naturally generated in piglin bastions.

Interlude 

1.17 and 1.18 only had a little bit of symbolism, so this is the jist. They introduced goats and more peak-y mountains in 1.17. They moved the goats up only to the snowy mountaintop biomes specifically in 1.18. Mountain peaks are used to symbolize eyes of the pyramid. 18 is 6+6+6. Elevating/exhalting the goat.

Part III

9-11/911 is a popular occult number sequence. The game's occult symbolism started in 1.16, which is 91*1 rotated upside-down. Originally, 1.17 was supposed to include everything that ended up spanning onto 1.19, but they completed it in 1.19, which also introduced most of the symbolism out of the three updates. 1.19 is 91.1 reversed.

The warden mob, the deep dark biome, sculk, and the ancient city structures represent Moloch in different ways. Moloch has traditionally been used to refer to the ancient Canaanite god of child sacrifice, though modern historians have recently concluded that the term was used by people at the time to refer to the act of child sacrifice. The similarities between the warden's design and Moloch statues, both in the modern era and ancient, are apparent. Its head's mouth is similar to that of the Moloch statue's mouth from Cabiria (1914). It has horns, and the sacrificial Moloch statue of yore was described has having a bull's head. Its stomach harbors floating souls, and Moloch statues were described as being furnaces with seven chambers ||used to sacrifice infants in||. There is the central space where souls can be seen, as well as the 6 spaces on the sides, in-between its ribs. When nearby, the player's vision disappears, with only the glow of the warden appearing in rhythm with its heartbeat. Drums were said to be beat during moloch, ||to mask the cries of infants from their parents||. This darkness effect repeats for 18 (6+6+6) seconds, but it only lasts for two thirds (66.6%) of that time. It is also the only mob in the game designed to be practically unbeatable by most players.

There are multiple types of sculk blocks that generate in the deep dark biome, all of which glow, most of which souls visible in their skins, and one of which has the first animated soul sprites in the game. The substance is used to summon the warden, which kills players, causing the sculk to spread, seeming to feed off of their "soul."

Part IV

Gematria is a form of occult & mystical Jewish numerology from language. "Skulk" is the universally-accepted spelling of a real word, while "sculk" is the one Mojang used for this newly-introduced substance. Tophet is a term used in the Bible to describe the location where moloch was practiced. In Hebrew gematria, the phrases "sculk," "tophet," "lucifer," and "satanas" all separately equal 323. In English gematria, "sculk" and "moloch" both equal 396.

The Bible describes moloch happening underneath overhanging crags, and in the same verse berates the same people of being "lusty" under oak trees. There is a new tree with a remarkable similarity to pre-existing oak trees in Minecraft, which, unlike every other tree in the game, has roots, which originally led specifically to deposits of a new, decadent crystal of the game, but now might just lead to a cave biome where those deposits are common.

The deep dark, which can be accessible to new players right off the bat if they dig straight down, is a new biome where sculk can be found, wardens can be summoned, and new ancient cities, which are covered in sculk, also generate. Mojang stated that the ancient city is inspired by Roman and Aztec ruins, which is interesting, since the first empire has records of religious deviants practicing child sacrifice, to the same god as described in the Bible further east, and human sacrifice was mainstream in the second empire. Though Rome can also be argued to have practiced human sacrifice in the Colosseum and similar arenas.

Ancient cities all have a giant altar in the center, which is a giant mouth of an early design of the warden underscored by soul fire, much like a furnace. Soul fire, which was introduced in the nether update, scares piglins, and due to it being the same color as souls, only occurring from burning soul sand, and soul campfires dropping faceless soul soil instead of soul sand with petrified faces of souls, suggests that it is souls being burnt.

Ancient cities' altars are the only location in the game where candles naturally generate as placed blocks, AFAIK, and candlelight is the preferred lighting of most occult rituals. The altar also bears a resemblance to the Moloch factory and monster in Metropolis (1927), with a central stairway leading up to the platform, a fire of sacrifice at the top along with a gaping mouth of a giant monster, and plumes of some form of heated water on either side of the entrance of the stairs. Additionally, both structures are in secret subterranean cities.

Allays, which are the game's first friendly, helpful spectres, were also added in the same update, and as shown in the following infograph, the Bible describes moloch and dealing with familiar spirits in the same verse. (2 Kings 21:6)

I haven't really checked out anything past 1.19 yet.