I wouldn’t begin with scientific arguments. I’d start with the biblical text and with Christian interpreters of the past.
Listen to the words of Origen (185–254):
Now what man of intelligence will believe that the first and the second and the third day, and the evening and the morning existed without the sun and moon and stars? And that the first day, if we may so call it, was even without a heaven? And who is so silly as to believe that god, after the manner of a farmer, “planted a paradise eastward in Eden,” and set in it a visible and palpable “tree of life,” of such a sort that anyone who tasted its fruit with his bodily teeth would gain life; and again that one could partake of “good and evil” by masticating the fruit from the tree of that name? And when God is said to “walk in the paradise in the cool of day” and Adam to hid himself behind a tree, I do not think anyone will doubt that these are figurative expressions which indicate certain mysteries through a semblance of history and not though actual event.
– Origen, On First Principles, ed. by G. W. Butterworth (New York, Harper and Row, 1966), p. 288