The event itself reveals what was before. The beginning of the universe. The expansion tells us that there was a beginning. The lack of thermal equilibrium tells us there was a beginning.Both red shift and cosmic background radiation point to an event that happened. Neither reveals what was there before, something or nothing, either is possible and neither has any evidence to support it.Do you know what red shift is? Or cosmic background radiation is?You don't know that, we only know something happened back then. If you suddenly found a puddle of water on the floor would you assume it 'popped into existence'. It may have come from melting ice or condensing steam. There is no way to know seeing only its current state.The universe popped into existence 14 billion years ago. Go ahead and argue against it.
And what the means in conjunction with Einstein’s field equations?
Did you just throw in Einstein’s field equations to obfuscate or is there really some point to mentioning them?
Friedmann’s solutions to Einstein’s field equations tells us there was a beginning.