That’s basically how Warp powers work in 40k.
In order to actually hurt someone with warp based attacks, you have to overcome your targets willpower. It’s normally not a problem for rank and file mooks.
You average guardsman isn’t going to really have a will to match a chaos space marine sorcerer, but something like a Grey Knight will. So, your random space wizard isn’t guaranteed to be able to roast someone with their mind.
You also need to have a “normal” soul. In universe, there are people called blanks, that essentially have an inverted soul. It makes them functionally immune to warp magic, and their mere presence hurts psychers.