What we think about matters. Satan wants us to believe that our thought life doesn't affect us or anyone else. That we can just entertain all sorts of evil in our minds and it is okay. But lust, worry, fear, anger and a multitude of other sinful thoughts will eventually work their way out of our minds and into our lives.
The Bible warns us about how dangerous our mouths can be. BUt rather than heed the warning about our tongues, we make excuses for why it is okay for us to say certain things and talk in this manner. We hide behind the lies of that's just who I am or this is my personality. But God has something else to say.
There is a battle going on between our natural man and our spiritual man. When we walk in the flesh, we quench the Spirit of God in our lives. Too often we are more okay with offending our spiritual man, then we are with our natural man. We need to learn to walk in the Spirit so that we do not fulfill the lusts of our flesh.
Society changes over time. What once was wrong becomes right, and what was right becomes wrong. But God and His Word never changes. As Christians, we can be pressured into accepting certain sins as okay, just because our cultural says that it is okay. Sin is sin, no matter what society says.
There is now no condemnation for the Christian that is walking after the Spirit of God. If you have trusted Jesus to be your Savior, then sin does not have control over you any longer. He has given us the victory over sin, and has made us more than conquerors through Him.