"As God's dear children try to be like Him and live in love as Christ loved us and gave Himself for us a fragrant offering and sacrifice to God. Sexual sins, anything unclean, or greed shouldn't even be mentioned among you. This is the right attitude for the holy people. No shameful things, foolish talk, or coarse jokes! These aren't proper. Instead give thanks. Ne sure of this, that no one who immoral, unclean, or greedy has any share in the kingdom of Christ, who is God. Don't let anyone fool you with meaningless words. These things bring anger and punishment on those who don't obey truth. So don't share their ways."
We live in a world that is so messed up, it can be hard to remember who we are, where we came from, what we are trying to do. It's not that we are trying to walk away, stuff just sneaks up on you. The stuff that you have been trying to avoid. The swearing, the dirty jokes, the mindless gossiping to fill the time at work. The list goes on. It's hard, being the light in the darkness. We tend to emulate what we see, often to our own detriment, and we don't even realize that it is happening.
It is pretty easy to slip back into the old habits that we had before we were saved. We tell ourselves that we do these things to fit in, to reach the world. That is just wrong. How can we be beacons of light in the darkness when we put out the same darkness that the rest of the world does? Don't focus on the worldly garbage that comes your way.
"Keep your mind on things above, where Christ is sitting at the right of God." Colossians 3:2
If we are keeping our focus on God, are you going to swear? Tell those dirty jokes? I think that if you truly keep your focus on God, you would find that gossip replaced by the Word.
I have a good friend at my workplace. He is such an encouragement. He fills himself with the Word. And when we get talking, he can quote verse after verse after verse. And not just the "big" ones, but the ones that you only find when you REALLY dig into the Word. He is not just a Christian in name; he lives it!
Spend your time in the Word. Don't neglect it. You can be that light on the hill, you just have to live your faith. Don't the let the world overwhelm you.