Belief in the oneness of Allah is the center of divine religions. This belief emphasizes the right of Allah towards its creatures and it is the cause of all successes in this world and the world hereafter. Due to its significant position, it is considered to be superior to all virtues and noble acts. In fact, acceptance of all deeds depends upon this belief. This belief has been discussed with all the necessary details in three books i.e. Torah, Gospel and the Holy Quran, so that their followers refrain from Shirk. Shirk is the opposite of Toheed and is strictly prohibited in all these religions. Divine religions put emphasis on the oneness of Allah and it is evident that all prophets gave one message to their followers and that message was of Touheed. This article discusses this significant belief with reference to three divine books i.e. Torah, Gospel and the Holy Quran. Hopefully this effort will be a valuable addition.