Energy can neither be created nor destroyed.
This concept was established be Einstein’s equation E=MC2 and has been confirmed by numerous experiments. Therefore Energy has always existed and will always exist, this means our current concept of time where everything has a beginning and an end is false. If we follow this line of reasoning it should be obvious that any scientific theory that describes the origins of the universe is not actually describing the origin of energy but rather one particular expression of that energy.
Science traces the origins of the universe to a timeless and motionless state called the Singularity. Since the Singularity is timeless, it cannot be talked about as before or after anything, if something exist but is not before or after anything then it is NOW. Therefore the Singularity is NOW.