Sin – What Exactly Is It?

The deadly spiritual disease that infected all humankind.


...just as through one man sin entered into the world, and death through sin, and so death spread to all men, because all sinned...

– Romans 5:12

Then she gave the fruit to Adam, and he ate. And immediately, they were aware of their nakedness and they were ashamed. Something terrible had happened. Something had changed. The evil in Satan was like an infectious disease. And through Adam’s disobedience, this disease was released into the world. It is called sin. It is a power that works within a person to destroy his or her relationship with God, ultimately bringing death to all it touches. Adam and Eve had been created to live forever in perfect harmony with God. By eating the fruit, they acted independently from God, which is exactly what Satan had done. Now they would experience death, first spiritually, then physically. And through Adam, sin would be passed down from generation to generation, infecting all humankind to this very day.

– The HOPE, Chapter 3

Observe & Consider

The word sin appears over 350 times in the Bible. It is most often used to identify an act against God (often referred to in the Bible as a transgression). One of the definitions of sin is literally, “missing the mark.”1 With this in mind, we could say that the “mark” is God’s way, and when we miss it, we are sinning.

Sin is also used in the Bible to describe the power that influences people to rebel against God’s authority. It is not only an act or an action against God; it is a personified power that influences us to act against God (see Genesis 4:7 and Romans 6:12-13). Through Adam, this deadly power spread to the whole human race.

You can see why The HOPE describes sin as being like an infectious disease.2 It can’t be diagnosed with medical technology because it is not a physical disease. It’s a spiritual disease, and it always brings death. And only God has the cure.

Ask & Reflect

Many people have the idea that all we must do to be right with God is be good. And a popular notion exists that anyone who manages to do more good than bad in life will go to heaven. The problem is that even if one lives a perfect life (which none of us can–Romans 3:23), that person would still be infected with sin, which is enough to keep us from having a right relationship with God. You see, it’s not only our “sins” that drive a wedge between us and God; it’s our “sin.” And just as we looked at Satan in Lesson 17 and determined that we are no match for him on our own, so also we cannot master sin without the power of God working in us.

  • Are there things in your life with which you struggle, perhaps even habitually?
  • Are there urges and desires in your life that you cannot eradicate, no matter how hard you try?
  • Having honestly answered these questions, do you find it difficult to believe that there is a power at work within you called sin?

Decide & Do

If you allow Him to do so, God will free you from the power of sin, and one day from the presence of sin entirely. But the choice is yours. You must accept His answer to the problem of  sin, confessing that you cannot overcome it in your own power. There is no other cure but God’s. He offers it to everyone as a gift. Have you received God’s gift?

Please understand that a gift is not a gift until you’ve received it. God’s gift and how to receive it are described in great detail in the Knowing God section at the end of this study guide.

For Further Study

For an in–depth study of sin as a spiritual disease, consider reading the following resources:

  • Dr. Bill Gillham, “The Power of Sin” from the November 1988 issue of Discipleship Journal. ( Retrieved October 6, 2006.
  • John Calvin, Institutes of the Christian Religion. ( See, in particular, point no. 5. Retrieved June 19, 2017. “Declaring that all of us died in Adam, Paul at the same time plainly testifies that we are infected with the disease of sin.”
  • William Perkins, The Art of Prophesying (1592, repr. Banner of Truth Trust, 1996, 54–55). As quoted by R. Scott Clark (Associate Professor of Historical and Systematic Theology, Westminster Seminary California), Classical Covenant Theology – Part 1: On Law and Gospel. ( Retrieved August 27, 2015. “The law exposes the disease of sin, and as a side–effect, stimulates and stirs it up. But it provides no remedy for it. However, the gospel not only teaches us what is to be done; it also has the power of the Holy Spirit joined to it.”
  • John Wesley, The Works of John Wesley, 14 Volumes, 5:449 (Peabody, Massachusetts, Hendrickson Publishing House, 1986). As quoted by Earl Robinson, Wesleyan Distinctives in Salvation Army Theology. ( Retrieved October 5, 2006. “The preaching of the gospel, on the other hand, is the offer of a physician for the disease of sin. Wesley said: ‘It is absurd offer a physician to those that are whole, or that at least imagine themselves to be. You are first to convince them that they are sick; otherwise they will not thank you for your labor.’”


1Charles C. Ryrie, Basic Theology (© Victor Books, a Division of Scripture Press Publications, Inc., Wheaton, Illinois, 1988, p. 212). “Indeed, it might be a good idea to define it [sin] thus: sin is missing the mark, badness, rebellion, iniquity, going astray, wickedness, wandering, ungodliness, crime, lawlessness, transgression, ignorance, and a falling away.”
2Billy Graham, “When Having It All Isn’t Enough” from the June 2004 issue of Decision magazine. ( Retrieved October 5, 2006.

Scripture quotations taken from the NASB