The jackstands are not meant to support the car indefinitely once it's lifted. The jack's only purpose is to temporarily lift the car.
Also, the jackstands won't bleed down like a jack can. I'd hate to be under a car when the jack starts lowering.
Proper lifting is using the jack to raise the car up, then lower it down onto the jackstands. The jackstands are MUCH SAFER than a jack.
If you don't have jackstands, run out and get a pair. Your friends/family will thank you not having to pay for a premature funeral when the jack fails with you under the car.