Jules Renard said “I don’t know if God exists, but it would be better for His reputation if He didn’t.” No one knows when religion and caste system exactly took its birth; but since its existence many people have followed one of the nearly 4200 existing religions among us. Religion is often a set of beliefs that tries to explain the nature, purpose and cause of our existence in the universe. Though majority of people have accepted it, there have been some strong arguments against religion even before science made its advent rationalizing thoughts. Diagoras, known as the atheist of Melos, presented a strong argument against religion as far back as in 1st century B.C. People who argue against religion often portray it as an outdated, discriminating, pertaining superstitious acts, immoral rituals and many more. It is true that religion is used as a political tool in the past and in present. Among the various arguments given against religion, I am trying to pick 6 strongest in the following article.