The biggest favor of Allah is Islam with which He has distinguished the mankind and Jinn. It is a single Deen which Allah made the last of all religions. He says: "Today, I have completed your deen for you, and perfected my favor upon you, and accepted Islam as a deen for you." (5:3) He also said: "And whoever seeks a religion other than Islam. It will never be accepted of him, and in the Hereafter he will be one of the losers." (3:85) Therefore, it is a responsibility of every Muslim to value this divine favor by adhering to it. This could not be possible without understanding all the aspects of the religion which should be based on the Qur'an and the Sunnah.
This is the reason for choosing this book, "The Pillars of Islam", explaining the basic fundamentals of Islam i.e., the two Testimonies, the Prayer, the Zakat, the Fast and the Hajj. It is written by a few research scholars of knowledge of the religion. It, being the most important subject to acquire knowledge of, is practiced by the tongue, the limbs, the heart and with one's wealth.