What does 2 Corinthians 2:15 mean?

Scripture has described the Christian life using an unusual metaphor in the previous verse. Paul pictured believers as captives of a Roman general returning in victory from war. In that era, generals would parade the conquered enemy through the streets while burning incense in celebration of the victory. This made the procession a combination of sight, sound, and smell, all of which proclaimed the victory of that commander.

Paul wrote that God parades Christians in this way, except that the spreading fragrance is not incense. It is the "smell" of the knowledge of God. Now Paul gets more specific: Christians are the aroma of Christ in the world. In a very real sense, believers make Christ present on earth, as He is in them. Everywhere they travel, they symbolically "give off the smell" of the Savior to fellow Christians and unbelievers alike. It's an aroma that is received differently depending on one's eternal status. This attitude greatly differs between "those who are being saved" and forgiven for sin in Christ, versus "those who are perishing" in sin without forgiveness because they lack faith in Christ.