O Mankind! verily there come to you a convincing proof from your God. For we have sent unto you a light (that is) manifest. (Quran)
Understand Holy Quran means that you should try to know why this book is sent towards us. Before Holy Quran and Islam people do not know what is the right way of life which leads to success , there were no life ethics and rules. Everybody was living according to his/her wish.
People were fighting on minor issues and things and these fights lasts even years and years and nobody knew why i am fighting that long and i should stop fighting and come to peace. There was no respect for women.
Instead of worshiping one Allah(GOD) people have many Gods and they are praying in front of them. In that darkness Holy Quran gives people a hope, a light of a new and changed life that is very pure and peaceful. That is why people started converting to Islam.
During 23 years of Holy Quran revelation people not only changed their habits but converted into new human beings who have no relation with the past. It is because of the pure teachings of Holy Quran that are no doubt are best suited for human beings.
Everyone must try to understand Holy Quran and its meaning in detail because this like a newsletter from Allah towards us.
One who understand it and act accordingly will be among the sincere peoples of Allah and is the candidate for the Heaven.
One who did not try to understand Holy Quran and its meaning and deny it will be among the disobedient of Allah and will be the candidate for jahanum ( Fire burning place whose fire is 69 times more strong than the fire of this world. Disobedient persons and stones are the burning source for it)