Nicolaitans comes from the Greek word meaning "adherent of Nicolas" (Strong's Concordance #G3531) or "destruction of people" (Thayer's Greek Definitions). This second definition is further confirmed when we break down the word Nicolaitans.
Niko is defined as a conquest or victory over others. The second part, lai, means people. The last part, tes, represents the word "the." Taken together, the word Nicolaitans means someone who is a conqueror or victor, a person who destroys the people.
Surprisingly, the Nicolaitans are only referenced twice in Scripture. The first time they appear is in God's spiritual assessment of the Ephesian church. He commends them by stating that they hate the works of these people which he, too, also hates (Revelation 2:6). The doctrines taught by them also are mentioned a few verses later, when the Pergamos church is called to repent because they firmly believe in this group's teachings (verse 15).
Who are they?
Early Christian writers Irenaeus [Against Heresies, 1.26.3] and Tertullian [Prescription against Heretics, 46] stated that the Nicolaitans were followers of Nicolas. The Nicolas in question, they believed, was one of the first seven specially chosen servants of the New Testament church (Acts 6:5). Although he was chosen to serve due to his character and wisdom, he later apparently began to promote false teachings.
What did the Nicolaitans teach, and how did they behave, that garnered God's correction and the threat of punishment to those who followed their evil ways (Revelation 2:16)?
"Like Simon Magus, whom the early apostles also confronted, the Nicolaitans introduced the concept of using the name of Jesus for commercial gain, dominance and control. After all, the concept had worked quite well in the pagan temples of the vast gentile world, generating wealth and revenue for many societies" (Nicholas and Xmas by C. Franklin).
In a church setting, these people attempted to set themselves up to rule over the lives and faith of other church members. They tried to force others to submit to their arbitrary position of authority that God never gave them and which he hates! The Apostle Peter warned that leaders among the church were not to dominate over the faith of others but rather exhort them to do right.
The elders who are among you I exhort, even as a fellow elder . . . Feed the flock of God that is among you, exercising oversight not by compulsion, but willingly; not in fondness of dishonest gain, but with an eager attitude; Not as exercising lordship over your possessions; but by being examples to the flock of God (1Peter 5:1 - 3).
The hierarchical teachings of the Nicolaitans openly reared its head during the Catholic Church's Council of Trent that was held between 1545 and 1563. During the council they stated, "If anyone shall say that there is not in the Catholic Church a hierarchy established by the divine ordination, consisting of bishops, presbyters and ministers, let him be anathema (a person who is to be detested and excommunicated)."
An evil structure
The entire top-down church administrative structure of the Catholics, as well as many other churches, owes its survival to maintaining what the Nicolaitans taught. Many "Christian" groups and denominations promote the belief in a strict church hierarchy where control over the people must be maintained and respected. The system they promote feeds on competition and strife among believers in order to take advantage of them at any time.
The Lord not only demands repentance from those who believe the doctrine of the Nicolaitans but also threatens severe punishment if they do not. God warns those who practice such lies, "Remember therefore from where you have fallen . . . or else I will come to you quickly and remove your lampstand from its place" (Revelation 2:5). May the warning be heeded!