In our circles today we could have unwritten "markers" by which we evaluate if someone does or doesn't appear to be a believer. Christ told his hearers that "fruit" in a person's life was a valid way by which to evaluate that person (Matthew 7:15-20; 12:33). But there can be other "markers" that we look for too. Paul warned that unrequired standards were "shadows," but "substance" was in Christ.