Where? Can you quote the verses in Revelation that say that the earth is a flat disc? I have just looked up the word "earth" in Revelation. It occurs 65 times, and not once does it mention the earth being flat. There is one verse that mentions the four corners of the earth:
“After these things I saw four angels standing at the four corners of the earth, holding the four winds of the earth, that the wind should not blow on the earth, on the sea, or on any tree.” (Re 7:1 NKJV)
But a flat disc doesn't have literal corners. As Barnes writes in his commentary:
"[Standing on the four corners of the earth.] This language is, of course, accommodated to the prevailing mode of speaking of the earth among the Hebrews. It was a common method among them to describe it as a vast plain, having four corners, those corners being the prominent points north, south, east, and west. So we speak now of the four winds, the four quarters of the world, etc."
Where does Genesis 1 mention the earth's shape? I can't find any verse in that chapter which does.