If we boldly live out our faith, the light of our lives (the light of Christ in us) will expose the sinfulness of others. This is because light exposes darkness. Of course, the light of Christ in me usually doesn't expose much darkness in those around me until it has finished exposing the darkness in me!
So here is a dilemma that maybe you didn't see coming. If the light exposes all the darkness in me and begins to expose the darkness in others - they are going to find me offensive, abrasive and probably pull away from me. This is most often observed when as we grow in spiritual maturity we tend to drift away from our friends who aren't.