Greetings!
Your last question is somewhat vague, in that I understand and agree with your comments, but I don't know if "we" means the world, or "we" means me, you, Christians, etc? If it is Christians, then I'd like to know specifically what you think Christians do that is hypocritical. I can think of some, but to ponder/respond to your question, I'd need more specifics.
When talking with this atheist, did your discussion lead in the direction that all cultures that we know about have similar basic principles of morality (caring for young, caring for the clan, cold murder is something to be punished, etc)? If they can agree to that, then there is evidence of a single source for morality, also proving Romans 1.