I usually give a synopsis of the Old Testament and how it led to the New Covenant. Then focus on the New and what it really means to us. Some folks refuse to be convinced, but the upshot is that it does me a world of good to engage.
I think folks sometimes tend to canonize what to them is the ordinary, not realizing that even what they are calling the ordinary is extraordinary. The ark of Noah would be a special case — it does not fit our ordinary expectations, but for the task it was purposed to by the Lord, it would not need to. Some groups, that we roughly sometimes call YEC (young earth creationists) actually have an entire interrelated thesis which doesn’t even need to be true to account for what we see in the scriptures. But as Job was admonished, who was present to watch the creation events. Humility before it is the only fitting attitude. Once humble, then God will fill in more details in a logical fashion. If we go proud, and some folks like Ken Ham have, we get pushed off course by the devil’s strawman arguments.