Equation of Sin

Sin can be illustrated by an equation, and that can help us understand it and reduce it.

By Mark D, Harris

Our Sunday School class is studying the New Testament book of James, written to the Jewish Christians of the diaspora by James the brother of Jesus in the late 40s AD. James was the pastor of the church in Jerusalem, and He provides powerful, practical advice for successfully living the Christian life. The first eight verses of chapter 1 discuss the Christian’s need for wisdom and God’s promise that He will provide it, so long as the believer asks in faith. Verses 9 to 11 mention the transitory nature of life, and the consequent even more transitory nature of riches.

James 1:12-18 takes a different track, discussing the nature of temptation and sin, and explaining that God cannot tempt or be tempted, but instead creates His people and provides every good thing for them. One could summarize these verses with the following equation:

Sin = choice x opportunity x self (with its sinful nature)

  • Sin is defined as disobedience to God.
  • Choice is the manifestation of the free will (and individual responsibility) that God gives us throughout life. Our lives are replete with choices small and large, easy and difficult, and these choices influence the subsequent course of our eternal sojourn. God is responsible for giving us choice.
  • Opportunity is the circumstance that may or may not precipitate sin. Opportunities may be external, such as when a man sees a beautiful, scantily clad woman at the beach, or internal, such as when a mental image of a former friend who hurt a woman long ago pops up in her mind. Seeing the woman or remembering the former friend do not themselves constitute sin. Due to His sovereignty, God is responsible for giving us opportunities.
  • Self is the root of our being, with its moral depravity because of original sin (v14). God is not responsible for the presence of wickedness in our hearts (v13). Adam and Eve contributed that from their rebellion in the Garden.

When we are presented with an opportunity, internal or external, our sinful nature warps that opportunity into temptation. If we choose to let it, sin is born (v15). Our evil nature gains power in that area. Our nature gains power when we sin because our neuronal and hormonal pathways adapt to make prior decisions and actions easier, and because we mentally and emotionally justify ourselves. Notice that the relationship is multiplicative. If we had no freedom of choice, no opportunity for temptation, or no sinful nature, we would not sin.

Suppose while rummaging through an old box, a widower comes across a photo of an old boyfriend of his late wife. The widower knew the old boyfriend, who was once his best friend. They dissolved their friendship fifty years before, fighting over the girl, and neither had ever tried to reconnect. The widower gazes at the picture and considers contacting his old friend. The widower remembers good times past and considers calling. Suddenly, dark memories creep into his mind. “I’ll never talk to him again!” the widower exclaims. The opportunity is the finding of the picture, the choice is to reach out in forgiveness or refuse to reach out and dwell in anger.

Choices, opportunities, and our sinful nature vary over time and with circumstances. Temptations vary: some people are tempted by alcohol or drugs, and others are not. Other people are tempted by worry or pride, and others are not. There is no virtue when a man who is not interested in alcohol refuses to take a drink, but there is great virtue when a woman who is prone to worry chooses peace and faith. Sexual temptations may be great in a young man, but much less in a septuagenarian. The equation of sin plays out in human life, so it is modified by common grace. The God who makes the rain fall on the evil and the good limits the amount and type of sin that people can commit both for the sake of mankind and for the rest of creation.

James 1:19-21 describes how the Word affects the equation of sin. On following Christ, the Word, meaning initially the teachings of God in the Bible and ultimately the person of Jesus Himself, becomes implanted in our souls. Through the process of becoming Christ-like (sanctification), the Word grows, and our sinful nature shrivels. We discover our vulnerabilities and learn how to avoid opportunities that will cause temptation. Our right choices make it easier to make right choices in the future. Thus, the Word of God in us affects every part of the sin equation, making us less likely to sin in the future. Our sinful nature weakens throughout life, though we are never free of it until death. With the Holy Spirit in us, the equation changes:

Likelihood of Sin = (choice – the nature of God in our lives) x (opportunity – the nature of God in our lives) x (sinful nature – the nature of God in our lives).  

Sin persists because we like it. Adam and Eve chose the forbidden fruit because they wanted to, and we do the same. Pride places us over other people, and we want to be above others. Lust reduces another person to a plaything, and we like it. Laziness grows out of our nature.

How do we facilitate God’s work in growing the Word in our lives? James 1:22-25 commands us to hear the Word of God in every way possible (preaching, teaching, Bible study, testimony of others, visual arts, music) and as often as possible. Then we must do what we have heard. The adage “learn by doing” is true in all areas of life, as that is how humans are wired. If we hear but do not do, we do not learn and ultimately delude ourselves. We forget ourselves as individuals, as members of our community, and as heirs to a long line of men and women. If we hear and do, we are blessed.


Knowing the components of sin and the process that leads to sin can help us avoid sin. If we adjust our thoughts, words, and actions to (1) limit our ability to choose sin, (2) reduce the opportunity to be exposed to things that encourage us to sin, and (3) weaken our sin nature directly, we will sin less. Everything about our lives, and our eternities, will improve. If only we would do it…


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