What Is Sin in Christianity? A Straightforward Explanation

In Christianity, sin is not just a bad action or a moral failure—it is disobedience to God's commandments. The Bible defines sin as "lawlessness" (1 John 3:4), which means going against the rules God Himself has given. These are not human inventions or cultural norms, but divine instructions meant to guide us into a just and holy life.

Christianity—and its Old Testament foundation in Judaism—is unique in that it presents a moral law given directly by God. The Ten Commandments (Exodus 20) are a clear example: do not murder, do not commit adultery, do not steal, do not lie, honor your parents, and so on. These are not vague principles. They are specific commands from a holy God who expects holiness from His people.

Other religions speak of right and wrong, or karma and consequence, but Christianity is distinct in how clearly it defines sin and its eternal consequences. Sin is not just about harming others—it is about breaking a relationship with God. That is why even sins done in private, like greed, envy, or lust, are serious in the Christian view.

Common examples of sin include dishonesty, theft, adultery, hatred, pride, and all forms of sexual immorality. But sin is not limited to big offenses. Jesus taught that even hatred in the heart is like murder, and lustful thoughts are like adultery (Matthew 5:21–28). Christianity shows that sin is not just what we do—it is also what we think and desire.

But the good news is that Christianity does not stop at defining sin. It offers a solution. Jesus came not just to forgive sin, but to break its power. The Bible says, “If we confess our sins, He is faithful and just to forgive us” (1 John 1:9). That is what sets Christianity apart—not only a clear definition of sin, but a Savior who can take it away.