So the devil and Jesus were on a mountain top sufficient to see all of the world's kingdoms
That is actually taking liberty with the text, since the passage does not say that from the mountaintop, it was "sufficient to see all the world's kingdoms".
What the passage does say is:
Mat_4:8 Again, the devil taketh him up into an exceeding high mountain, and sheweth him all the kingdoms of the world, and the glory of them;
Luk_4:5 And the devil, taking him up into an high mountain, shewed unto him all the kingdoms of the world in a moment of time.
Notice, that the devil took Jesus up into an exceeding high mountain, and "sheweth" Jesus "all the kingdoms of the world, and the glory of them", even "in a moment of time". Several things then:
[1] the devil "sheweth", which means the devil presented the kingdoms (all of them) through a medium of vision
[2] it was "in a moment of time", which means a brief panoramic view took place
[3] there is no mountain high enough, even on a so-called flat earth model to "see" "all the kingdoms of the earth" at once, and their "glory", for even the so-called flat earth believers, understand about optics, field of view, haze, density of atmosphere etc, and so, even in their so-called flat earth model, it would not be possible even with direct line of sight, upon the highest place upon the so-called flat earth model.
See the word similarly used in Acts 7:3, in which God showed Abraham the promised land through vision (Genesis 15:12-13; John 8:56). See also Revelation 17:1, 21:9, 22:6, for another angel "shew[ing]" another person events and places in vision, or panoramic, even symbolic view. For instance, we use television, internet, etc to view many places all at once, and the devil, and heavenly angels are more sophisticated than we, for mankind was made just below the angels.
The devil is able to give not only dreams (Job 4:13), but also visions (Ezekiel 13:16).
and "the four corners of the earth" is spoken of in Revelation.
I must assume you mean to be referring to:
Rev_7:1 And after these things I saw four angels standing on the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, nor on the sea, nor on any tree.
The book of Revelation is given in symbol, primarily, and uses many types even from the old testament texts.
If you study the Bible more closely, on the term "corners" it is also used for the human head:
Lev_19:27 Ye shall not
round the corners of your heads, neither shalt thou mar
the corners of thy beard.
The human head is not flat, but roundish.
Moreover, the phrase "four corners" is directly associated with the altar of burnt offering/sacrifice/slaughter, of which the earth represents, since it is the place in which Christ Jesus died. It also has to do with the simply four cardinal directions, North, South, East and West, which exists upon a spheroid earth.
The number "four" is also symbolic of the 'universal of both place and time', hence the 4th commandment, dealing with all things created and the time in which it was created. Many examples could be given in scripture to substantiate this, but only as needful. One may begin in Genesis 2:10, even and see the 4 great rivers flowing from out of Eden, which watered all the earth. There are four metals in the statue of Daniel 2, Gold, Silver, Brass, Iron, representing the 4 kingdoms from Babylon unto the end (Roman).
Of course, the earth has no corners
You are mistaken, since the 'earth', aka the "dry land" (Genesis 1:9-10), has many 'corners', even 'ends', many 'boundaries', ect.
Job_28:24 For he looketh to
the ends of the earth, and seeth
under the whole heaven;
Exo_13:20 And they took their journey from Succoth, and encamped in Etham, in
the edge of the wilderness.
Be careful then of the language used, in its context, locally, and globally, otherwise, you might make very grave mistakes, for read this passage over-literal, and once comes to a funny ideology:
Eph_2:20 And are built upon the foundation of the apostles and prophets,
Jesus Christ himself being the chief corner stone;
Jesus is literally a stone block? or is it using a special type of language to get the point across that everything begins with Jesus?
Joh_1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
Jesus is literally a fuzzy woolly sheep? or is it using language referring to something else that we may obtain the idea that Jesus is the sacrifice required of the true sanctuary service?
Even still, on a so-called flat earth model, the land itself does not have 4 corners, but has four ice walls, which are not earth, and in other so-called flat earth models, there are no corners at all, since they say that there is an infinite beyond the ice wall (thus no corners to speak of. Depends on the so-called model one is dealing with, for none of them agree, which is another sign it is not from God, for it breeds confusion, and unnecessary division.
and no mountain top would be sufficiently high to see 'round the world.
Agreed, not with normal sight, and not even on a so-called flat earth model either. Atmosphereic conditions, air pressure, particulates, lighting conditions, etc.
I pray you do not want my thoughts, but what God has said in His word. A plain thus saith the Lord.
