Okay let's assume that the universe right now exists. At the time you're reading this, everything in the universe is in a certain state and so the universe as a whole exists in a certain state. Necessarily, every thing in the universe must exist in exactly the state it does for the universe as a whole to exist in exactly the state it does. If anything right now did not exist, the universe as is would not exist. This is a necessary existence. The universe exists, but if any of the things composing it did not, it would not be the universe, it would be a different universe.
Let us also assume the universe existed five minutes ago. Everything composing the universe five minutes ago existed, but nothing composing the universe we currently are in existed, as in the intervening time everything composing the universe, and the entire universe itself, changed into a different thing.
So if the current universe exists, everything composing it has to exist, but clearly also does not have to exist as it did not five minutes ago.
Hopefully it's becoming clear to you that the distinction is arbitrary and dependent on our perspective, and any sort of discussion or debate based on the distinction is also completely arbitrary and dependent on our perspective.