A 90-year-old pregnant woman?

BABYMAKER. Thoughtful souls read the Bible story about God coming to earth to tell Abraham that his 90-year-old wife was going to have a baby. Then they ask questions.Art by Christian Wilhelm Allers.

IF YOU PUT A BIBLE in the hands of one Christian and another Bible in the hands of a non-Christian, then you ask them each to read the same story, who do you believe would do the most thinking about what they’ve read?

Here’s what I’m wondering. Would the Christian tend to skim through the story, accepting as fact everything that’s printed, while the non-Christian would raise intelligent questions all the way through the story?

Take the story of God and two celestial associates suddenly showing up in the camp of Abraham. God tells Abraham that

Abraham’s 90-year-old wife is going to have a son within the year
and God is going to Sodom to see for himself how sinful the city is.

I think most Christians would breeze through that story in Genesis 18 and believe everything they read.

But I don’t think people outside the faith would agree. They would pause to do some serious thinking about that story.

When I write books about the Bible I try to think like people outside the faith or new to the faith.

Here are a few questions I think they might raise as they read that story. I mention the questions because I believe we Christians need to be willing to think with those folks.

Why should we believe that Sarah delivered a baby at age 90 or 91 when the oldest person on record to deliver a baby in modern times was 70-year-old Omkari Panwar of India, who gave birth to twins and died three years later?
Why does God have to come down to earth to check out Sodom, “to see for myself if those people really are that bad” (Genesis 18:21)? That sounds like a god in Greek mythology, not an all-powerful God who knows everything.
Why does God have to toss around in his head whether or not to tell Abraham that he’s going to Sodom to lower the boom: “The Lord said, ‘Should I hide from Abraham what I am about to do?'” (Genesis 18:17)?
How did the writer know what God was thinking?
Why should I not read this like a work of ancient fiction intended to add some color to the story of the legendary founder of the Jewish nation? Is there any harm in believing this is fiction?