1 Corinthians 8:8 "Do I say these things as a mere man? Or does not the law say the same also?"
1 Corinthians 8:19 "For though I am free from all men, I have made myself a servant to all, that I might win the more."
The background for this chapter is that many people (Corinthian believers) were struggling with their own gray area. The example used is the one of believers buying inexpensive meat to eat that had been offered to idols in Pagan practice. Some of the believers felt it was okay while others thought that demonic entities could be in the food and then could enter your body as you consumed it. There was no scripture to lay claim to either side of the argument so it was a huge gray area for the people. Johnny Mac throws out some examples that are current in our times, drinking alcohol, playing sports on Sundays, styles of music, wearing make-up for woman, playing the lottery, etc... All these things are seen as a gray area to many believers. Paul clears this up in the end with this idea (v 23, v 24, v 25-27, v 28-30). He basically says that Christian Liberty should be seen as edification over gratification (v 23), others over self (v 24), liberty over legalism (vv 25-27), and condescension over condemnation (vv 28-30).
My personal opinion on this matter is that these gray areas are not a deciding matter in whether or not one can be saved/salvation therefore like Paul says we should not condemn ourselves or others with regards to these issues. If you're feeling unsure about an issue or gray area in your life pray diligently about it and let the Holy Spirit guide your heart. If you can honestly say that you have no conviction in correlation to your actions, I would assume you're alright. Remember that this only applies to gray areas (issues that are not written about in the Bible), knowing myself I've tried too many times to apply this principle to areas that are spoken about in the scriptures only to learn a tough lesson.
Blessings!