No problem with the first two sentences. The third seems incautious and not agnostic.
Beyond the Big Bang, concepts like "before" are inadequate. We're four-dimensional entities in a four-dimensional universe, and our comprenension beyond that is as limited as would be the comprehension of of our reality would be to three-dimensional entities in some planar universe.
If we say without qualification "there was no before," prior to the Big Bang, we're also saying "there was nothing and no one."
This might sound like semantic niggling, but if science isn't attentive to the theological ramifications of certain statements (especially at the boundaries of space-time), we're never going to escape the tar baby of the false science vs. religion dilemma.
