Do not be unequally yoked with unbelievers. For what partnership can righteousness have with wickedness? Or what fellowship does light have with darkness? — 2 Corinthians 6:14

Paul's question cuts to the heart of the believer's identity — light and darkness have no fellowship. You were once darkness, but now you're light in the Lord; Christ came as the Light of the world so whoever believes in Him wouldn't walk in darkness. The Gospel doesn't just clean you up — it transfers you out of one kingdom and into another. So don't yoke yourself to what Christ has already delivered you from. The love of God and the love of the world simply can't coexist.