Two more facts for your Christian friend to dismiss.
Christians like to say that something cannot come from nothing so god did it.
In fact something is trying to come from nothing ALL the time. It is part of the basic structure of the universe that it does that. Around black holes particles are actually successful in coming into existence.
Christians are quite fond of this word - nothing - and they like to say what it means and what it's implications are. With each new scientific discovery Christians like to change their definition of what the beginning was and what nothing was. No air, no space, no time etc. Some early definitions of nothing came about through Greek and Roman philosophy and that led to the dramatic opening of the bible translated into English as - in the beginning god created heaven and earth.
It might come as a surprise to some that the full stop was not originally there. The exact translation of the original which should be in your bible as a footnote is, - when god began to create heaven and earth, everything was watery chaos...(the last two words are a paraphrase of a long sentence). The bible actually says that everything was a watery chaos before god did anything then later god separated the waters into heaven and earth etc.
This should also give an idea of the meaning of the flood story of Noah. The original chaos of the universe is being allowed back to destroy everything.
So when your Christian friend says everything cannot come from nothing, remind him 1) it does and 2) the bible does not say the universe came from nothing.
No doubt the next excuse will be that the original waters were their way of saying quantum fluctuations because they look like rippling water.