God settled Satan as well as Adam on the earth and gave due warning in the very beginning that clashes of interest between the two would go on till Doomsday. Satan would make every possible effort to mislead mankind, therefore, people should make it a point to treat him as their greatest enemy and try to stay far away from his inducements. To give further guidance to man, God periodically sent him His messengers, or prophets, who instructed him in the reality of life in a language which was clearly intelligible to him. Now, the success or failure of man depends on his own acceptance or rejection of the Prophet’s guidance. One who accepts this guidance will once again be ushered into the comfortable life of paradise, whereas the life of one who fails to accept it will be a very severe one, from which he will never be able to escape. Those who turn away from God’s guidance will be reduced in the Hereafter to blindness, being deprived of both the eyes. The reason for this is that such people are given eyes in the world in order to be able to see and recognise God’s signs. But they live in such a manner that, when they encounter God’s signs, they fail to recognise them. Thus, they prove that, in spite of having eyes, they are really blind. So God will ask on that Day, what use it had been to give eyes to those who were determined to be blind.