Crept in unawares (3921) (pareisduno. from pará =beside, at the side of + eisdúo = enter in <> eis = into + dúo = go down, sink) is a vivid verb which means "to go down into and alongside of" and settle down alongside those already there. And so Jude depicts these false believers slipping in secretly as if by a side door, going into and alongside of, settling down alongside those already there (in the faith), sneaking in and sitting on the same row as believers. Bogus believers cloaked in counterfeit faith and piety. They didn't come in via the door but another way (Jn 10:1) Barclay on "crept in unawares" - The Greek (pareisduno) is a very expressive word. It is used of the spacious and seductive words of a clever pleader seeping gradually into the minds of a judge and jury; it is used of an outlaw slipping secretly back into the country from which he has been expelled; it is used of the slow and subtle entry of innovations into the life of state, which in the end undermine and break down the ancestral laws. It always indicates a stealthy insinuation of something evil into a society or situation. Certain evil men had insinuated themselves into the church. They were the kind of men for whom judgment was waiting. They were impious creatures, godless in their thought and life. Jude picks out two characteristics about them. (Jude 1 - William Barclay's Daily Study Bible) They come in secretly, without notice, like a thieves (and their effect would be like that of a thief!!! Loss would occur to those who listened to their lies). Spiritual leaders grow complacent, careless or concerned about nickels and noses had better be warned: danger lurks around the next pew. So Jude was BLOWING THE TRUMPET call to alert the troops of Jehovah. These false brethren would say you are saved by grace so go for the gusto. Live as you please. Anything goes. After all, all you have to do is "confess" it. They promised freedom but it was the kind of freedom that led to terrible bondage (2Pe 2:13-14, 19-note). This verb occurs only here in Scripture. These certain men had slipped in, stealing in undercover, as under the cover of darkness (if the light of God's Truth is dim it makes it easier for them to creep in.) Thus the importance of men and women in the body who are LIGHTS because the light shines into the darkness and the darkness does not overcome the light (Jn 1:5). In fact when exposed to the light of Christ, ''rats'' tend to flee for cover (Jn 3:18) and may even leave completely. The TRUTH exposes The LIE, so once again the critical importance of holding fast to the Word of Life, the Word of Truth. (Titus 1:9) Crept in implies an "inside job," and that these purveyors of error are even now among the brethren. Paul had warned the elders of the church at Ephesus "I know that after my departure savage wolves will come in among you, not sparing the flock and from among your own selves men will arise, speaking perverse things, to draw away the disciples after them" (Acts 20:29—30-note) Spurgeon - They did not boldly avow their heresy when they came in; — they would not have been allowed to enter if they had done so, — but they sneaked in, they climbed into the pulpit, professing to be preachers of the gospel, when they knew, all the while, that they intended to undermine it. Basest of all men are those who act thus: “There are certain men crept in unawares,” Proscribed by God as traitors long ago. Those who have not the courage of their convictions probably have no convictions at all, but seek to undermine the faith which they profess to hold. Antinomians, “turning the grace of our God into lasciviousness,” falsely declaring that the law has no binding force upon the Christian’s life, and saying that we may do evil that good may come; — and Socinians, “denying the only Lord God, and our Lord Jesus Christ.” See similar descriptive verb in 2 Peter 2:1 = Secretly introduce = pareisago [word study]] Only here in New Testament. The kindred adjective occurs Galatians 2:4, "false brethren secretly brought in" (pareisaktos: 3920 = relates to someone joining a group with false motives or false pretenses). The metaphor is of spies or traitors introducing themselves into an enemy's camp. Compare Jude 1:4, crept in unawares. The verb means, literally, to bring into (eis) by the side of (para). Wuest - There is a Greek word in 2Cor 11:13—15 which admirably describes the methods of the Modernist, who takes after his father, the Devil. It is metaschematizo, translated “transformed”. It refers to the act of an individual changing his outward expression by assuming an expression put on from the outside, an expression that does not come from nor is it representative of what he is in his inner character. Lucifer did that after he struck at God’s throne and became the fallen angel, Satan. As a fallen angel he gave expression to his sin-darkened heart. But he knew that he could not attract the human race that way. He must impersonate God if he expected to be worshipped as God. He therefore assumed an outward expression of light, put on from the outside and not representative of his inner sinful being. He disguised himself as an angel of light. His ministers, (servants), Modernistic preachers, have done the same (v. 15). Using evangelical terms such as “salvation, faith, regeneration, atonement, resurrection,” they put their own private meanings upon them (which negate the orthodox view), and pose as orthodox exponents of Christianity. Reader, do not trust a Modernist any farther than you would a rattlesnake. A rattlesnake will give you warning before it strikes, but not a Modernist. The eternal welfare of your soul depends upon what you believe regarding the person and work of our Lord on the Cross. Those who were long beforehand marked out ("Long ago the Scriptures predicted the condemnation they have received." = TEV; men spoken of in ancient writings as pre-destined to this condemnation = WEY) - These false teachers did not surprise God Who wrote beforehand about their coming and their condemnation even before they existed.