@Nadeem Khan,
(Many) years before (the) Cape of Good Hope was discovered, Columbus had formed (the) idea of reaching (no determiner) India by sailing towards (the) west (no determiner) across
(the) dreaded Atlantic Ocean.
Unlike most men of
(the) day he believed (the) world to be
(a) sphere, and (the) study of
(his) father in law's logs and charts had led him to think that he could easily sail to (no determiner) India from (no determiner) Portugal.
But (the) distance proved to be much greater than he thought, for he did not know that between (no determiner) India and (no determiner) Portugal lay (a) great unknown continent.
Slowly he became more and more strongly convinced of (the) mission.