"They're not going to fire you" isn't always true. I have known one person who has been fired for asking for a raise. The exec involved only needed to do this

"They're not going to fire you" isn't always true. I have known one person who has been fired for asking for a raise. The exec involved only needed to do this once, because it was talked about among employees for years and probably dissuaded a hundred others from asking for raises.