"Therefore, since we cannot empirically test whether space and time have always existed, we, being the sciencists that we are, MUST reject the theory that the universe has always existed (and God as well)."
You cannot reject the theory that the universe has always existed simply because you cannot test it at this point in time. You definitely cannot prove the universe has always existed just as you cannot prove that the universe appeared one day using todays best scientific methods.
That does not invalidate the possibility that the Universe has always existed. Like I said the laws of thermodynamics state that no energy or matter can be created or destroyes. If this law is correct, the only possibility is that the universe has always existed.
If you can disprove the laws of thermodynamics you may have a foot to stand on, otherwise the universe must have always existed.
"You cannot reject the theory that the universe has always existed was designed by an intelligence simply because you cannot test it at this point in time. "
"You cannot reject the theory that the universe has always existed God exists simply because you cannot test it at this point in time."
"You cannot reject the theory that God is the intelligent designer of the universe has always existed simply because you cannot test it at this point in time."
I'll remember that the next time I see ID'ers bashed for their lack of scientific proof, lol!