A Flat-earth believing Christian writes of Job 38
God talking to Job: Where were you when I made the foundations of the earth? Declare if you have understanding. Who has the laid measures thereof if thou knowest or who has stretched the line upon it? (not around it). Whereupon are the foundations thereof fastened (how can the foundations be fastened on a spinning ball?). or who laid the cornerstone thereof.
This is God talking to Job. God’s words and not man.
Firstly, I do not consider one passage of scripture of more or less authority than another. It is all God’s Words. In the book of Job when Job is speaking about what God has done, He is speaking under the inspiration of the Holy Spirit. That is the only reason he knows anything (e.g. Job 26:7).
All scripture, not some scripture, is inspired by the Holy Spirit.
All scripture is given by inspiration of God [literally means God breathed from the Greek original text], and is profitable for doctrine [teaching], for reproof, for correction, for instruction in righteousness:2 Timothy 3:16 (KJV)
Also God is sovereign and He promised to preserve His Words so that none will ever be corrupted or lost.
The words of the LORD are pure words: as silver tried [refined] in a furnace of earth, purified seven times. 7 You shalt keep them [His words], O LORD, You shall preserve them from this generation for ever. Psalm 12:6-7, KJVER
Looking at Job 38:4-6: (KJVER)
4 Where were you when I laid the foundations of the earth? declare, if you have understanding.
5 Who has laid the measures thereof, if you know? or who has stretched the line upon it?
6 Whereupon are the foundations thereof fastened? or who laid the corner stone thereof;
There is also Job 38:18 talking about the breadth of the earth (how big it is).
Have you perceived the breadth of the earth? declare if you know it all.