As Jeff said, there is no inherent row order in tables in Oracle.
It does not matter what order you *try* to insert records into a table, they may or may not actually get inserted in that order. Further, when you try to SELECT these same records back out, you may or may not get them in the order that they exist in the table.
The only way to guarantee the order of rows inside the table itself is to make it an index-organized table. Even then, the order of the records once SELECTed cannot be guaranteed.
Simply put, you *need* an ORDER BY in any SELECT if you care about the order. Period.