An airbag can hurt you some if they deploy in a wreck.
However the injury and pain from the airbag is nothing when it's compared to a potential injury or even death from a car wreck without the airbag.
I was once in a wreck and when the airbag deployed from my steering wheel I got a bruise on my face and it stung for about 30 minutes.
But after 30 minute the pain and stinging went away and I was okay afterwards.
If I hadn't had the airbag deploy the injury would have probably been a lot worse.
So yes the airbag can hurt when they deploy but they can save lives as well.