Is cheating on a test or on school work sin? Is it a small sin that God will overlook?
The Apostle John gives us an accurate definition of what sin is in 1 John 3:4 which says “Everyone who makes a practice of sinning also practices lawlessness; sin is lawlessness.” There it is; sin is lawlessness but what law is John writing about? He is surely talking about the Ten Commandments  but also about the command to love one another that Jesus gave which was a new commandment (John 13:34). Sin was no gray area for John as he wrote “whoever does not practice righteousness is not of God, nor is the one who does not love his brother” (1 John 3:10b) and this makes it evident “who are the children of God, and who are the children of the devil” (1 John 3:10a). Sin is missing the mark and falling infinitely short of God’s righteousness which is what all of us do (Rom 3:23).
We are new creations in Christ just as Paul wrote in 2 Corinthians 5:17 which says “if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come.” The fact that we are now new creations in Christ means that “No one born of God makes a practice of sinning, for God’s seed abides in him, and he cannot keep on sinning because he has been born of God” ( John 3:9). Paul, in speaking of himself and the church when he wrote “we have the mind of Christ” (1 Cor 2:16) and the mind of Christ will not chose to make a practice of sinning. Many people have deceived themselves into thinking that since they are under grace, they can sin as they like. That is a dangerous place to live my friends. Paul asks, “What shall we say then? Are we to continue in sin that grace may abound?” and then answers his own question, “By no means! How can we who died to sin still live in it” (Rom 6:1-2)? It is “just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life” (Rom 6:4) and thus “We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin” (Rom 6:6).
To Cheat or Not to Cheat: Gray Area?
I can remember years ago in one of my college classes, the professor in our ethics class asked for a secret ballot poll with the question “Is it wrong to cheat on college work?” The professor assigned a student to count the choices and someone else to write it down. It was a clear majority as 80% said that it was wrong to cheat on college work, meaning one in five think it’s okay but the numbers of those actually cheating are much higher than 20%. The reports of college students cheating is nothing new. The surprising thing will be when you don’t hear about it. Even in the world of business, it’s perfectly acceptable to hedge the books or move funds around for evading taxes but just because something is common practice or is done by the majority of people does not mean it is acceptable to God. What is popular is not always right and what is right is not always popular.
There are many things that some believe are sin but at the same time, the Bible is silent. To cheat or not to cheat is not a gray area to me. It is as black and white as possible. Esau was cheated out of his birthright by Jacob  (Gen 27:36). Moses told “Only not let Pharaoh cheat again by not letting the people go to sacrifice to the Lord” (Ex 8:29). The cheat has God’s curse on them in one case (Mal 1:14). Paul addressed what some call the gray area by writing that “whoever has doubts is condemned if he eats, because the eating is not from faith. For whatever does not proceed from faith is sin” (Rom 14:23). There is nowhere in the Bible that condones cheating in any shape, manner, or form. Jacob was cheated out of his wages (Gen 31:7) because he reaped what he sowed. In similar fashion, the person who cheats will reap the wind, one way or another
The word “conscience” means “with” (con) “knowledge” (science) and everyone’s been born with a conscience that tells them when they’ve done something wrong or done something right. Someone that keeps repressing their conscience will have it seared sooner or later by the callousing effect that sin has on the heart. I feel less pain on the callouses on my hands but under my fingernails, now that’s sensitive! Sin desensitizes us to the Holy Spirit’s conviction. We can grieve the Holy Spirit (Eph 4:30) by participating in sinful practices over time, just like violent video games and movies desensitize the viewer to violence slowly but surely over time. James writes “whoever knows the right thing to do and fails to do it, for him it is sin” (James 4:17) which would also mean that if anyone knows the wrong thing to do and does it anyway, for them it is sin.
Imagine how you would feel (again!) if someone sold you something that wasn’t worth the price. They had effectively cheated you. It hurts to be cheated on doesn’t it…but when we cheat we hurt ourselves and certainly others. I believe this is not even close to being in a gray area. The Bible is not silent on this subject but quite vocal. This is not a matter of my opinion but upon Scriptures and biblical principles, morals, and ethics. We have no excuse if we cheat on anything in life, whether a small quiz, a final example, a “white lie” or a fabricated tax deduction. No matter how you try to rationalize it, God will not bless anyone who cheats on anything. They will reap what they sow, even if it’s later than they sow, but the harvest time will come; for good or for bad and in due time.
Read more here: Are Some Sins Greater Than Other Sins? 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), copyright © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.