Luiz has often been criticised and was one of several players below par in the 3-1 thumping at West Ham that has turned up the heat on boss Rafa Benitez.
Angry words were exchanged in a stormy dressing-room inquest.
But Luiz said: "Having words with someone is something positive for the team and the players have to feel comfortable with it.
"I knew the responsibility of wearing the Chelsea shirt when I came here. But I got it into my head that I could never let myself be intimidated by the fact that the club had big names."