Don’t worry, Allah will expose the fake people. Allah tells us this in the Quran. He will bring out their hatred even if they assume He won’t. (Quran 47:29).
People who have hate and spite for others tend to hide them. They are the people who meet you with a smile and say salam but they have ill feelings about you. You will never know that they have these bad feelings about you.
These people expose their feelings in other people’s gatherings. When they among your other friends they will talk about you but when they meet you it is all good.
Allah describes this as a disease of the heart. Disease of the heart is more than just not remembering Allah. People who resent others have a disease in their hearts as well.
They think they can hide it from everyone. However, Allah will expose it. If someone makes a comment you don’t like, don’t hide it. Deal with it in a good way because that way it will not build resentment up inside of you.
We have to learn to resolve things with each other without offending people.