One of the challenges of living a life that pleases God is avoiding sexual immorality, and though Paul never specifically uses the word "purity," I believe it is implied in 1 Thessalonians 4:3-8. Paul does say that God doesn't call us to live "impure" lives, so the implication is that we are to put a life of purity on a pedestal. It's pretty interesting that Paul doesn't just say that the Thessalonians need to abstain from sex. No, his message is deeper than that: seek purity. What's the difference? One attitude looks at refraining from one specific behavior, the other attitude addresses an issue of the heart. Truth be told, immorality starts in the heart and makes its way out through the body. James tells us that each of us sins when we're dragged away by our own evil desires (James 1:14) – a heart issue. God's desire is for His people to have pure hearts, and we get a glimpse of the condition of a person's heart by the actions in his. How is your heart? Are you on a pursuit of purity? Remember that purity starts in the heart.