Yes an airplane can glide safely even when the engines fail on the plane.
If you have a really good pilot who is very experienced they can safely glide the plane and land it if there is a spot to land the plane even when the engines fail on the plane.
It's very rare that both plane engines will fail but in the event that both engines on the plane do fail the plane can be glided safely.
So you won't just crash to the ground when the engines on the plane fail unless you have a non experienced pilot operating the plane.
Airlines hire very experienced pilots who have very extensive training flying airplanes so you're in good hands when on a plane with an airline.
I was on a commercial airplane before and one of the engines did fail and the plane was able to be glided and flow safely with the one engine and the pilot was able to land the plane safely.
That really scared me though but the pilots on the plane assured us that we could glide safely and land the plane safely with just one engine and even without any engines running.
But anything can happen and the plane could crash but it's rare that a plane crashes even though we hear of airline crashes.
There are thousands of successful flights everyday that make it safely without crashing.