The words deceit, deceitful, deceitfully, deceitfulness, deceive, deceived, and a few other similar words appear well over 100 times in the King James Version of the Holy Scriptures. Their frequent appearance indicates their importance.
The word “deceive” means “to cause (someone) to believe something that is not true, typically in order to gain some personal advantage.” The word “deception” is defined as “the act of deceiving someone.” [All definitions are from the On-Line Dictionary.] Just a casual survey of these words and their meanings should show the seriousness of both being deceived and of being guilty of deceiving someone. Let's look at a few Bible instructions concerning these things.
First, it is obvious that some people intend to deceive others. Paul warned the saints at Ephesus, “That we henceforth be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men, and cunning craftiness, whereby they lie in wait to deceive” (Eph. 4:14). Of the greatest mistakes that any Christian can make is to assume that teachers of error are sincere. It may be true that some are, but for the most part this is certainly not true. This verse and its description of false teachers and their motives should forever silence the claims of sincerity on their part. “By the sleight of men” indicates trickery in order to deceive. “Cunning craftiness” means “skill in achieving one's ends by deceit.” “Lie in wait to deceive” shows their purpose and that they are completely aware of what they are doing. The language used here makes any apology for the deceivers a senseless endorsement of evil: William H. Taylor wrote, “Our translation is inadequate. The meaning is: they make use of every shifting device to mislead. There are not only those around you who lead you astray but mean to do it. They lay deliberate traps on purpose to guide you away from Christ whom they do not love” Beacon Bible Commentary, p. 211.
Other passages also support this conclusion. Paul said, of those who are to be “marked” because they “cause divisions and offences contrary to the doctrine,” that they “serve...their own belly; and by good words and fair speeches deceive the hearts of the simple” (Rom. 16:17-18). Job said of these types, “their belly prepareth deceit” (Job 15:35). In II Corinthians 11:13, Paul speaks of deceitful workers transforming themselves into the apostles of Christ. He then goes on to point out that satan's “ministers also be transformed as the ministers of righteousness” (II Cor. 11:15). These “ministers of satan” are guilty of “wresting the Scriptures” (II Pet. 3:16) and “handling the word of God deceitfully” (II Cor. 4:2). Punishment awaits all such deceivers. Peter said “they bring upon themselves swift destruction,” and “their judgment lingereth not, and their damnation slumbereth not” (II Pet. 2:1, 3).
But wait―there is another side to all of this. You and I are taught that we must not allow ourselves to be deceived. “Take heed that no man deceive you” (Matt. 24:4). “Let no man deceive you with vain words” (Eph. 5:6). “Let no man deceive you by any means” (II Thess. 2:3). “Little children, let no man deceive you” (I John 3:7). “Take heed that ye be not deceived” (Luke 21:8). “Be not deceived” (I Cor. 6:9; 15:33; Gal. 6:7). It obviously is the Christian's responsibility to grow up in Christ and not permit himself/herself to be manipulated and/or misled by these false teachers. We all have the Holy Scriptures which are able “to make thee wise unto salvation” (II Tim. 3:15). Thus we are to “Try the spirits” (I John 4:1). We are to “Prove all things; hold fast that which is good” (I Thess. 5:21). So, let all of us “search the scripture” to see “whether these things are so” (Acts 17:11).
We are even warned about falling victim to self-deceit, which is the worse kind of deception. “Let no man deceive himself” (I Cor. 3:18). “If we say we have no sin, we deceive ourselves, and the truth is not in us” (I John 1:8). “...he deceiveth himself” (Gal. 6:3). ”...deceiveth his own heart” (James 1:26). “Be ye doers of the word, and not hearers only, deceiving your own selves” (James 1:22).
In closing, I believe the words of Peter sum up our responsibility along this line. “Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour” (I Pet. 5:8).