All praise is due to Allah, Who only gives the criterion of justice to the most pious among scholars and intellectuals. It is He Who sent messengers bearing glad tidings of reward and warnings of punishment and He also revealed to them divine books containing perfect laws free from any deficiency, blemish, or fault, which explained the wrong and the right.
I praise Him as one who knows that He is the causer of all causes praises Him, and I sincerely testify to His oneness without a trace of doubt. I also bear witness that Muhammad is His slave and messenger whom He sent when disbelief hung like a veil on the face of belief. He removed the darkness with the light of divine guidance, lifted the curtains of ignorance and explained to the people what was revealed for them. He clarified all which was unclear in the Qur'an and left Muslims in a clear state, free from any distortion. May Allah's peace and blessings be on him, on all of his family and companions, and on all those who righteously follow in their footsteps until the Day of Resurrection and Judgement.
Surely the greatest God given blessing to humankind is the intellect, because it is the sole instrument by which God, Most Glorious, is known, and the only way by which belief in the Prophet is realized. However since the intellect can't take responsibility for everything humankind requires, messengers were sent and divine books were revealed. That is, the divine law is like the sun and the intellect like the eye which sees the sun, if the eye is open and healthy. When the true message of the prophets is accepted by the intellect after exposure to miraculous proofs, it submits to the prophets and depends on them for understanding the hidden and unseen world.
After blessing the world of man with intellect, Allah began humankind's earthly existence with the prophethood of 'Adam, peace be on him, who taught his descendants according to divine revelation. Humankind remained on the right path until Cain separated himself from the path of righteousness by following his desires and killing his brother. Subsequently, uncontrolled desires split people into factions and drove them into the wilderness of misguidance and the worship of idols. Many contradictory beliefs and practices which were incompatible with the message of the Prophets and confusing to the intellect arose among them. By following their desires, customs, and the influence of their leaders, people confirmed the Devil's wish - that they would all follow him except a handful of believers.
It should be realized that the prophets brought a crystal clear message which they successfully used to confront, the illnesses of society and to effectively cure them according to a common methodology.
However, Satan came and introduced ambiguities into the clear message, mixed poison with the cures, and obscured the straight path by creating around it countless deviant paths. Down through the ages Satan continued to play with people's minds until they fragmented into a multitude of absurd denominations and sects based on despicable innovations. Some eventually worshipped idols in and around the very Ka'bah, the first house of worship built for the worship of the One God, Allah. The Arabs made certain animals forbidden to themselves like the Sa'ibah, a she-camel left to graze freely; the Bahirah, its female offspring whose ear they used to slit; the Wasilah, a sheep which had given birth seven times each time delivering twin females; and the Hamm, a stallion-camel dedicated to the gods according to certain rites. They also buried their baby daughters alive, and deprived orphans of their rightful inheritance, etc.
Allah then sent Muhammad, may Allah's peace and blessings be on him, who cancelled these detestable practices and introduced laws for the benefit of mankind. As for his companions, they travelled by the light of his guidance, during his lifetime and after his death safe from the Devil and his enticements. But when the daylight of their presence faded and the shadows of darkness fell, desires returned, innovations arose and the clear wide path became narrow. Most people split their religion into factions and the Devil rose to the occasion, obscuring, deceiving, embellishing, dividing and fabricating. For, the Devil's deception can only take place in the dark night of ignorance. If the dawn of knowledge rises his deception is easily exposed.
I decided to warn people about Satan's cunning strategies by pointing out his traps because the exposure of evil is a warning against falling into it. In the Sahih of al-Bukhari and Muslim there is a hadith related by Hudhayfah in which he said, "People used to ask Allah's Messenger about the good but I used to ask him about the evil for fear of it catching hold of me." 'Abdullah ibn 'Abbas was also reported as saying, "By Allah, I do not believe there is any one on earth today whom the Devil would like to see dead more than me." When he was asked why that was so, he replied, "By Allah, when the Devil makes an innovation in the West or the East and a man carries it to me I counter it with a sunnah and it returns to him as he sent it."
Consequently, I wrote this book to warn people against the trials of the Devil. I sought to frighten them by removing the Devil's mask and by exposing his evil tactics. And, Allah helps everyone who is truthful and whose intentions are wholly sincere.
Source: Introduction to The Devil's Deception