What is Sin and Why Should I Fight It?

In order to know how to fight sin, you first need to know what sin is and why you should fight it. And, even further, in order to know why you should fight sin, it’s important to understand the core problem of sin.

Our core understanding of sin is found in why we believe sin is bad in the first place. Someone may ask, “I know what some specific sins are, but why is this particular action a sin while this other action is not?” Or, “Why did God have to decide this option was sin and this option was not sin?” Does God simply decide what is good and what is bad? What is sin?

Defining Sin

To start, the words “good” and “bad” are made up terms that humans use to assign certain actions their place on the Godlike vs un-Godlike scale. If an action is considered (biblically) good, this means that the action is accurately reflecting an attribute of the nature of God. If an action is considered (biblically) bad, this means that the action is a rejection of a certain attribute of God. 

God is not subject to anything, including some super philosophical, high level concept called “goodness.” Instead, He is the very definition of it. So no, God does not simply decide what is good and what is bad, and then proceed to enforce these rules upon us. God’s very nature defines what is good and what is bad, and these rules are naturally enforced upon us by the fact that God has designed us in His Image (Ephesians 4:24, James 3:9). 

When we sin, we are not simply doing a bad deed. We are actively splitting ourselves off from what we were designed to be and the goodness that encompasses who God is. From the vertical perspective between us and God, I’m sure one can at least begin to imagine why God might find sin so offensive. We are not rejecting a moral code; we are rejecting Him.

The one who rejects me and does not receive my words has a judge; the word that I have spoken will judge him on the last day.
-John 12:48

You are good and do good; teach me your statutes.
-Psalm 119:68

What Does It Mean to Reject God?

It is important to understand that we are completely and utterly separated from God, because He is just. There is something within our nature that causes us to know with full certainty that a crime deserves punishment. Our sin is a crime against the law, order, and design of God’s universe, and it is no exception to this rule (Galatians 5:19-21). Sin deserves punishment, and there is simply no other way around it.

While this vertical separation can often go unnoticed by mankind, sin’s horizontal effects between people are more commonly noticed. One word of harsh arrogance in a quick burst of anger can destroy years of friendship. Sin has proven time and time again that it damages relationships and hurts others. However, it also hurts us, and this leads us into one thing many Christians do not fully grasp: God also hates sin because he loves you.

And you were dead in the trespasses and sins in which you once walked, following the course of this world, following the prince of the power of the air, the spirit that is now at work in the sons of disobedience—among whom we all once lived in the passions of our flesh, carrying out the desires of the body and the mind, and were by nature children of wrath, like the rest of mankind. But God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved.
-Ephesians 2:1-5

The Lord knows that it won’t go well for you if you choose the “passions of the flesh.” It’s just not the way He designed it to be! As Tim Keller puts it, 

Because a fish absorbs oxygen from water, not air, it’s free only if it’s restricted to water. If a fish is ‘freed’ from the river and put out on the grass to explore, its freedom to move and live is destroyed. Real freedom isn’t restrictionless; it’s finding the right ones.

God gives us these “right restrictions,” also known as a biblical definition of what is good and what is bad, so that we may be able to find true life in His goodness.

For all have sinned and fall short of the glory of God, and are justified by his grace as a gift, through the redemption that is in Christ Jesus whom God put forward as a propitiation by his blood, to be received by faith. This was to show God’s righteousness, because in his divine forbearance he had passed over former sins. It was to show his righteousness at the present time, so that he might be just and the justifier of the one who has faith in Jesus.
-Romans 3:23-36

Now What?

So far, we have focused on the nature of sin itself and the way that it affects the natural man. But after looking at the nature of mankind’s relationship to sin prior to faith in Christ, it is important to remember that once a believer is “born again,” sin in itself does not change. The believer’s relationship to it does, and therefore, their responses to sin should look different than the rest of the world’s. In my next article, I will discuss the way Christ’s church ought to approach sin, but for now, I think it’s safe to conclude that sin is not good. It hurts us, it harms others, and most of all, it separates us from the God who in Himself defines the love, joy, peace, and hope that we all long for. 

Yet for some reason, sin is what we are naturally inclined to (Romans 8:5-8). After all, you don’t have to teach a toddler how to lie; they just do it. Humans are quite literally the only part of creation that willfully refuse to submit to God’s rule (Romans 8:19-21). It is for this reason (among countless others) that we ought to be very grateful for the Gospel. We do not even understand the vastness of our own depravity, and we cannot grasp the exact depths of the nature of our sin, yet God loves us and showcases who He is by revealing his grace, mercy, love, and justice to us through the cross, so that by faith we may be restored to a right relationship with Him (Rom 5:8, 5:1-2,11). As we fight sin, let us praise God for his faithfulness, and let us praise God for his righteousness. He alone is truly good.

The Mission

To conclude, notice how Paul describes to us in Galatians his own persistence in the “crucifixion of the flesh.” I do not believe he was simply attempting to make a pithy statement for the sake of exhibiting the Holy Spirit’s (remarkably impressive) talent for metaphors. Instead, Paul knew that the Church was designed for war. In fact, before the beginning of time, the Bride of Christ was ordained by God to be His instrument of warfare against all of the ungodliness within His creation. Throughout history, the Church has misdirected this towards other nations, other faiths, and other people instead of rightly directing it towards the reality of our own fleshly sin that so easily entangles us (Hebrews 12:1-3). 

I urge you to join God in His mission to wipe evil off the face of the earth. Let us take our place in the eternal struggle as we begin to wage war within our very own hearts and minds. It is true that there will be a day when there will no longer be any reasons to fight sin, because there will be a day when sin will no longer exists. But, though the hour is approaching perhaps more quickly than we think, that day is not yet here. So for now, we fight. We fight because the war is already won through Christ, and we fight because God has given us the opportunity to be a part of the battle today. Now, the question is no longer “Why should you fight sin?” Instead, it’s the exact opposite.

Why would you not?