There is a problem with this argument, because you bring God into it, which is a matter of theology and philosophy.
Sean Carroll was arguing about the human framework of reality as we have it nowadays, which has nothing to do with the existence of God in what manner whatsoever.
And with adding on the above i can make a statement on the topic:
Differencing between belief and knowledge as agnostics do is from a logical standpoint a more truthful to human reality approach, than trying to prove something based on -> (individual) beliefs based on -> constructed truths , as atheists/christians tend to do.
On the other hand that doesn't say whoever has more faith, which you cant determine in a philosophical manner, anyway. You could try do that with a neurological measurement in an experiment, but the forum has no means to do that