To do an insert on specific columns (as opposed to all of them) you must specify the columns you want to update.
INSERT INTO USERS (FIRST_NAME, LAST_NAME)
VALUES ('Stephen', 'Jiang');
This will only work if the columns that you did not list are nullable, identity, timestamp data type or computed columns; or columns that have a default value constraint. Therefore, if any of them are non-nullable, non-identity, non-timestamp, non-computed, non-default valued columns...then attempting this kind of insert will trigger an error message telling you that you have to provide a value for the applicable field(s).