Do Christians have faith in oxygen/air?

[Nay_Sayer]

Okay, so now I'd distanced myself from the church for a few months now.

Three months ago, my partner asked me if I had faith in the air we breath.

Of course my answer was no, because it is obviously and irrefutably there.

You could guess what that person asked next! 

Next question was: "So why do you have faith in God?"

Thinking about that question for several weeks now, and I'm having a strange feeling. 

Am I overthinking because I can't think of a strong answer? What am I missing?

You're missing the one true god, Obviously. Then you have a strong response.