Why did people first begin to believe that the earth was a sphere

People today still debate weather earth is still round or flat. It’s science vs what the Bible said, at least from what I’ve heard, science explains how the earth was made is is just proven facts...but also what people tell me the way the Bible explains how the earth looks like has other people believing that earth could be flat. And yes NASA has pictures of outer space a former worker have proven that SOME not all but SOME of the pictures were fake. Or it could be some other thing this is just my input on it :)

2. is bettergo with that