"You are of your father the devil, and the desires of your father you want to do. He was a murderer from the beginning, and does not stand in the truth, because there is no truth in him. When he speaks a lie, he speaks from his own resources, for he is a liar and the father of it." (John 8:44) Our adversary, the devil, is the father of all lies. It all began in the Garden of Eden when he added the little word NOT to God's command.! From that time, until the end of time, the devil will use his lies to destroy God's children and those in the world. Let's consider a few of the lies he most often uses to deceive men.
One sin doesn't matter. Satan really uses this lie to his own advantage, and millions of people have convinced themselves it's true. He glorifies sin, tells us that God really loves us, and that sin in moderation doesn't hurt anyone. The Bible very clearly refutes this lie. "For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord." (Romans 6:23) How many sins does it take to cause spiritual death? How many did it take for Adam and Eve? (Genesis 3) Nadab and Abihu? (Leviticus 10:1-3) King Uzziah? (2 Chronicles 26) Moses? (Numbers 20) All unrighteousness is sin (1 John 5:17). God does not fellowship sin (1 John 1:6-10). The truth is: ALL sins, even one, matter.
Nobody will know. Satan convinces people that they can hide their actions from God and other people. While it is true that we can hide some sins from other people, we cannot hide them from God. "In the day when God will judge the secrets of men by Jesus Christ, according to my gospel." (Romans 2:16) "And there is no creature hidden from His sight, but all things are naked and open to the eyes of Him to whom we must give account." (Hebrews 4:13) One could also read Psalm 33. We can fool and lie to men and no one may be the wiser. The bigger worry is that the only one who truly matters does know all that we say and do.
Everybody sins-we can't help it. John Calvin's Total Depravity theory-men sin because they're naturally evil-helped to make this lie even more widespread. Calvin was wrong, but sadly he's influenced a vast majority of the world to believe that we sin because we are unable to stop ourselves. "Therefore submit to God. Resist the devil and he will flee from you." (James 4:7) The key lies in learning to say NO. We all sin, but not because we have to; it's what we choose to do !
Old Satan has mastered these, and so many more, lies to deceive the simple into believing that sin is a small matter. How could something packaged as being fun and harmless cost Christ's life on the cross? It seems to me that God made a powerful statement about His hatred for sin when He allowed His son to die for all of us (Hebrews 2:9). Could it be that Satan just told us another lie?