Qur'an is the guide of a reasonable person. When one acts out of the Qur'an, he/ she would lose reason as well, may Allah forbid. Success is certain when one acts in line with the Qur'an. Allah explains this many times in the verses. Allah says "you would certainly be victorious." But one should patiently and resolutely abide by the Qur'an. - Harun Yahya