According to the Quran, there are two major parts of Islam—religion (din) and the law (Shariah). Din or al-din is basic and absolute, always remaining the same, without the slightest change. It is obligatory for all believers, whatever the circumstances, and entails belief in the One God, and the worship of Him alone. The Shariah, on the other hand, may differ, depending upon times and places. That task in reality is not synonymous with bringing about a change in the shariah but it is only a reapplication of the shariah in terms of altered circumstances. The task of effecting such reapplication, which was undertaken in the past, will in like manner, continue to be carried out in the future. It is this process of continual adjustment which helps to keep Islam permanently updated. In the present book Maulana Wahiduddin Khan explains how to apply the shariah of dawah in present times.