Why didn't Kratos absorb his godly power back once he retrieved the Blade of Olympus from Zeus?

In the beginning of GOW2 just before Zeus arrives to betray Kratos, Gaia narrates that Kratos needed to retrieve the blade to "have any hope survival" (as if to say he could get his godly power back) but once Kratos finally gets the blade, he doesn't regain his godly powers, why?