Proverbs 10: 18
Hiding hatred makes you a liar:
slandering others makes you a fool
"But I don't say it out loud!"
I think that everyone (or most everyone) has a person that they don't really like that well. It could be a family member, co-worker, 'friend', celebrity (they are people too)... whomever.
Even if we don't voice our dislike or 'hatred' out loud, doesn't mean that it's not a sin to feel that way about them.
We see in this proverb that it is as much of a sin (lying) to hide hatred as it is to verbally announce it (slandering).
We have to watch our hearts. Hidden anger/hate can turn our hearts cold. It can cause us to clam up/get sick to our stomach/ say things we wouldn't normally say... etc.
If we have any hatred in our hearts and are trying to hide it (God can see even in our hearts), we need to pray really hard to God to heal us of that negative emotion. With His help, we can get rid of that hatred and start loving our neighbor. Everyone is our neighbor... whether we 'like' them or not.
God Bless You!