"And a servant of the Lord must not quarrel but be gentle to all, able to teach, patient, in humility correcting those who are in opposition, if God perhaps will grant them repentance, so that they may know the truth, and that they may come to their senses and escape the snare of the devil, having been taken captive by him to do his will." (2 Timothy 2:24-26)
Notice the first part of this verse - "And a servant of the Lord must not quarrel but be gentle to all, able to teach, patient..." Only by utilizing these traits of the Holy Spirit will you truly walk as a "Light among men". God is the sole Judge and Jury when it comes to sin in people's lives. It is not up to us to condemn anyone, but only to do what He has directed us to do in His Word. Regarding your "example" I would suggest that you be a "Light among men" by showing them you walk with Jesus by your words, thoughts, and actions. We do not walk as examples of Christ when we condemn people or show animosity toward them simply because of their lifestyle. Remember that Jesus died for such as these and while we should not tolerate such things within our own lives (or our churches) we should still "be gentle to all, able to teach, patient, in humility correcting those who are in opposition" in the manner that the Lord has directed.
The rest of the above verse can even be used as a prayer, such as, "Father, I pray that You would grant [insert name here] repentance, so that they may know the truth, and that they may come to their senses and escape the snare of the devil, having been taken captive by him to do his will."
Amen.