I agree with the other statements to the effect that flying is definitely not as safe as driving a car, and that it is very much dependent on the pilot how safe (or not) it is.
If you want to convince anyone that it is not downright dangerous when you want to entice them to go along for a ride, you need to argue credibly how you are reducing the risks.
These are the arguments that I use:
- I ensure that I keep in practice, and won't bring any passengers if I'm not nor will I fly as PIC if I don't feel physically up to it,
- I fly docile/reliable/tried-and-tested aircraft, which I am current on and am convinced are well-maintained and operated by a serious operator,
- I regularly practice forced landing and/or engine-out approaches, and have regular check rides with an instructor,
- I do a thorough pre-flight inspection, and if I'm in doubt that something's not OK, then there's no doubt: I'm not going,
- I will only fly in weather conditions which are well within personal and legal limits, and if there's any doubt, then there's no doubt: I'm not going or will turn back.
- I acquire a comprehensive and appropriate weather briefing before the flight, and check NOTAMS,
- I do a thorough pre-flight planning (W&B, endurance, T/O length required), even more so in hot and high conditions,
- I brief the passenger thoroughly about anything that will/could happen during a flight, before it occurs (e.g. how to open the door),
- I don't admire the countryside below me during the flight much, only to keep a look-out for potential landing sites, and prefer to keep my head on a swivel looking out for other aircraft