“Whoever believes in him is not condemned, but whoever does not believe stands condemned already because he has not believed in the name of God’s one and only Son.” John 3:18
There is an important difference between unbelief and doubt. Doubt is a questioning of faith and so, by definition, it is something that only believers can do. “Doubting Thomas” was a disciple of Jesus.
Unbelief is different. It is a settled refusal to believe. When a person says, “I don’t believe! I won’t believe! I can’t believe!” What lies behind that? What is the pathology of unbelief?
The issue here in John 3:18 is that some do not believe. Why don’t they believe? What lies behind a person’s unbelief? “This is the verdict: Light has come into the world, but men loved darkness instead of light…” (3:19).
The roots of unbelief lie in loving the wrong things.
God made us to love. He made us to love him and to love each other. All his commandments are summed up in these two things: Love God with all your heart and love your neighbor as yourself.
The effect of sin is that we love the wrong things. Paul says that in the last days people will be “lovers of themselves, lovers of money… [and] lovers of pleasure rather than lovers of God” (2 Tim. 3:2, 4). This will be the effect of sin getting into the human bloodstream.
If you love self, or money, or pleasure, you will not believe in the Lord Jesus Christ, because he calls you to deny yourself, take up your cross, and follow him. So long as you love yourself, your money, or your pleasure more than you love Jesus, you will not believe and follow him.
Do you see some of the roots of unbelief in yourself? How so?