I think we see this far too often in the world. People who say they are Christian, but then their actions would seem to indicate otherwise. Look, nobody is perfect. There may be times when a car cuts us off, a co-worker or spouse lashes out at us in anger, or we are hearing about a Hawaiin trip a buddy of ours is taking. Without thinking we "lash" back out at the co-worker or spouse, we let fly a choice word or two for the driver that cut us off, and we can't help but turn green with envy as "we've" never been to Hawaii. We're human. Sometimes we'll react emotionally, but therein lies God's forgiveness when we ask for it.
The larger problem is when these "reactions" aren't reactions at all, but in fact are standard operating procedures for you. You often go into fits of road rage when somebody is driving too slow or is taking a little too much time to get going after the light turns green. You often get into heated arguments with friends and strangers about politics or a divisive social issue. You often gossip, are jealous of, and even put down colleagues or friends in front of others. And your vocabulary (whether spoken or on social media)? Well, let's just say it would make a rapper blush.
It's one thing to say you "know" Jesus, but it's another thing to make sure you're LIVING like you know Him as well. In all circumstances in your lives we need to ask what would Jesus do? How would Jesus respond in this situation? Would Jesus use these kinds of words I'm about to use whether in anger or even in fun? Would Jesus seek out a flirtatious relationship with someone who is not your spouse? Would Jesus get into a drunken stuper because "I'll just have one more"? Believers, and especially "non" believers, are watching your every move. You are a son or daughter of God. The Holy Spirit is living in you and knows your every action AND thought, so remember that when a difficult or tempting situatuon comes along.
If you say you know God, then live a life where your actions and words are a "magnet", not a repellant, to ALL those around you, so you can then share about the goodness of our Lord and the story of salvation that can only come through a relationship with Jesus Christ.