It means not laughing along with some perverted joke. It means not cussing with all of the 'cool' kids. It means not standing back and letting people make fun of being Christian. It means telling people what you believe when they ask, and when they don't. It means not cheating, lying, or being inappropriate. And ITS NOT EASY, trust me.
When you do these things, odds are that you are going to get 'persecuted'. It says plain and simple in 2 Timothy 3:12, "In fact, everyone who wants to live a godly life will be persecuted." So let's pretend that you did all those things already. Hopefully you hang out with people where those things are totally acceptable, and in that case, you are really fortunante. I consider myself blessed to be with both kinds, my friends I normally am with are great Christians that I love, but on the swim team I hang out with people who are good, but not exactly Christian good. I love them just as much, if not more, but that's a different story. Anyway, odds are you are at some point around people that you want to look 'good' near. You want to fit in, we all do. But when you do the things I talked about before, they are going to persecute you. They might leave you out of the next event, or turn your back on you right then and there. It hurts. But let me share a story with you.
Long story short: the Apostles were telling people about Jesus. They then suffered ridicule from the officials and high priests, who made them look stupid. They were even put in jail for a while. But then, in Acts 5:41, it says, "The apostles left the Sanhedrin, rejoicing because they had been counted worthy of suffering disgrace for the Name." It doesn't sound hard, when you read their story. But I dare you to do this challenge, and then say that it's easy. Because it's not.
Do something that will get you persecuted.
Stand up to some people who keep on cussing. Tell people that it's not okay to make fun of the church and what we believe in. Let them know that you are on God's side, and not the devil's. And if you do it right, they will persecute you. Maybe you'll be fortunate and they will embrace it, finding Jesus in their lives again. That would be even better. But be prepared to be an outcast, a loner, and closer to God. Because it is WORTH IT. I mean, how can an eternity of happiness and love in heaven not be worth a few hardships here on this temporary earth?