One of the biggest things we need to be concerned about is having a heart that doesn't feel anything. We're warned about this in Revelation 3:15-16: "I know your works, that you are neither cold nor hot. I could wish you were cold or hot. So then, because you are lukewarm, and neither cold nor hot, I will vomit you out of My mouth."
Sometimes we may think we're doing the right thing by not reacting to something sinful - But the truth is, we're not. If we're not going to stand up for what is right, we might as well be the ones laughing at the dirty jokes. God doesn't want a "closet Christian" - He wants somebody who is "ON FIRE" for Him! God gave us hearts that were meant to respond and when they stop doing that very thing, we're in serious danger. If our hearts don't feel anything, it's "high time to awake out of sleep" (Romans 13:11).