Why did Israel get suckered into the idolatry of Peor, at the instigation of Balaam (Num 25:1-3, Num 31)? Perhaps Balaam convinced them that they were already chosen; they had already been delivered from death by the blood of the Passover lamb and had gone through the Red Sea (1 Cor 10:1-2). They were already in covenant with the Lord God, cut at Mt. Sinai. Did not God just bless them and prophesy awesome and wonderful things about them (Num 23-24)?

Therefore, their identity as His people, he may have argued to them, negated the necessity of “works befitting repentance” (Act 26:20), a doctrine which the Lord declared heretical by killing those who indulged in the doctrine of Balaam with a plague from His hand (Num 25:1-9). If this is a correct understanding of the doctrine of Balaam, then this heresy is closely related to that of the Nicolaitans.

“[The doctrine of Balaam] is stated in the subsequent part of the verse: ‘Who taught Balak to cast a stumbling-block before the children of Israel.’ … The meaning here is, that it was through the instructions of Balaam that Balak learned the way by which the Israelites might be led into sin, and might thus bring upon themselves the divine malediction. … The attitude of Balaam’s mind in the matter was this: i. He had a strong desire to do that which he knew was wrong, and was forbidden expressly by God. ii. He was restrained by internal checks and remonstrances, and prevented from doing what he wished to do. iii. He cast about for some way in which he might do it, notwithstanding these internal checks and remonstrances, and finally accomplished the same thing in fact, though in form different from that which he had first prepared. This is not an unfair description in what often occurs in the plans and purposes of a wicked man.”

Albert Barnes, Notes on … Revelation, pp. 75-76.

Christine’s note: Barnes makes a cogent case that Balaam’s sin was in obeying the letter of the law while violating the spirit of it.

“Compare Re 2:14, 15, which shows the true sense of Nicolaitanes; they are not a sect, but professing Christians who, like Balaam of old, tried to introduce into the Church a false freedom, that is, licentiousness; …”

Jamieson, Faussett, and Brown, Commentary, Revelation 2:6.

The Nicolaitans embraced the antinomian heresy, or, that since salvation is by grace through faith, obedience to the Law is of no value.

Antinomian : one who holds that under the gospel dispensation of grace the moral law is of no use or obligation because faith alone is necessary to salvation.

Webster’s Dictionary.

Neander (History of the Christian Religion, as translated by Torrey, i. pp. 452, 453) numbers [the Nicolaitans] with Antinomians … [and] that the name … is used … to denote corrupters or seducers of the people, like Balaam.

Albert Barnes, Notes on … Revelation, p. 67.

“To the angel of the assembly in Pergamum write:” Rev 2:12.

“The early people of the town were descendants of Greek colonists, and as early as 420 bc they struck coins of their own. … Attalus I (241-197 BC) … adorn[ed] the city with beautiful buildings until it became the most wonderful city of the East … Art and literature were encouraged, and in the city was a library of 200,000 volumes which later Antony gave to Cleopatra. The books were of parchment which was here first used; hence, the word ‘parchment,’ which is derived from the name of the town Pergamos. … When in 133 BC … the last king … died, he gave his kingdom to the Roman government. … and the Roman province of Asia was formed, and Pergamos was made its capital.   … Of the structures which adorned the city, the most renowned was the altar of Zeus, which was 40 ft. in height, and also one of the wonders of the ancient world. … A title which it bore was ‘Thrice Neokoros,’ meaning that in the city three temples had been built to the Roman emperors, in which the emperors were worshipped as gods. Smyrna, a rival city, was a commercial center, and as it increased in wealth, it gradually became the political center. Later, when it became the capital, Pergamos remained the religious center. As in many of the towns of Asia Minor, there were at Pergamos many Jews, and in 130 BC the people of the city passed a decree in their favor. Many of the Jews were more or less assimilated with the Greeks, even to the extent of bearing Greek names.”

“Pergamos; Pergamum,” International Standard Bible Encyclopedia.

“Pergamum continued to rank for two centuries as the capital, and subsequently, with Ephesus and Smyrna, as one of the three great cities of the province; and the devotion of its former kings to the Roman cause was continued by its citizens; who erected on the Acropolis a magnificent temple to Augustus. … Pergamum was the chief centre of the imperial cult under the early empire, and, in W. M. Ramsay’s opinion, was for that reason referred to in Rev. ii. 13 as the place of ‘Satan’s throne.’ It was also an early seat of Christianity, and one of the seven churches.”

“Pergamum,” The Encyclopaedia Britannica, Vol. 21, p. 143.

Sexual immorality and eating things sacrificed to idols were part and parcel of pagan idolatry.

“The special enticements to idolatry as offered by these various cults were found in their deification of natural forces and their appeal to primitive human desires, especially the sexual … Baal and Astarte worship, which was especially attractive, was closely associated with fornication and drunkenness (Amos 2:7 , Amos 2:8; compare 1 Kings 14:23 f), and also appealed greatly to magic and soothsaying (e.g. Isaiah 2:6; Isaiah 3:2; Isaiah 8:19 ).”

“Idolatry,” International Standard Bible Encyclopedia.

“It seems strange to a modern reader that with these ceremonial prohibitions [against idolatry] should be connected the strictly moral prohibition of fornication. … no heathen moralist, not even Socrates, or Plato, or Cicero, condemned fornication absolutely. It was sanctioned by the worship of Aphrodite at Corinth and Paphos, and practiced to her honor by a host of harlot-priestesses! … Hence the author of the Apocalypse also closely connects the eating of meat offered to idols with fornication, and denounces them together.”

Philip Schaff, History of the Christian Church, Vol. 1, pp. 294.

“Ancient Near Eastern societies … featured many shrines and temples or ‘houses of heaven’ dedicated to various deities. According to the 5th-century BC historian Herodotus, the rites performed at these temples included … what scholars later called sacred prostitution. … The Hebrew Bible uses two different words for prostitute, zonah (זנה)‎ and kedeshah (or qedesha) (קדשה)‎. The word zonah simply meant an ordinary prostitute or ‘loose woman’. But the word kedeshah literally means ‘consecrated’ (feminine form), from the Semitic root q-d-sh (קדש)‎ meaning ‘holy’ or ‘set apart’. Whatever the cultic significance of a kedeshah to a follower of the Canaanite religion, the Hebrew Bible makes it clear that cultic prostitution had no place in Judaism. Thus the Hebrew version of Deuteronomy 23:17-18 tells followers: ‘None of the daughters of Israel shall be a kedeshah, nor shall any of the sons of Israel be a kadesh. You shall not bring the hire of a prostitute (zonah) or the wages of a dog (kelev) into the house of the Lord your God to pay a vow, for both of these are an abomination to the Lord your God.’ Stephen O. Murray writes that biblical passages ban qdeshim and link them with gods and ‘forms of worship detested by orthodox followers of Yahweh’.”

“Sacred Prostitution,” Wikipedia.

Public holidays in the ancient world were both religious and national in character. The attendant rites which accompanied pagan idolatry, including animal sacrifice, were integral to the celebrations. This practice had come down from the original corruption of religion at Babel.

“Nimrod, being the founder of both their civilization and their religion, served as king, and chief priest. The later kings of Sumer (as Shinar is known today) followed his example in this, as in all else.”

Christine Miller, The Story of the Ancient World, p. 40.

“The ritual alone which accompanied divination practices and incantation formulae was a chief factor in the celebration of festival days …”

“Babylonian and Assyrian Religion,” The Encyclopaedia Britannica, Vol. 3, p. 115.