Badges mark quoted or attributed material (Qur'an, hadith, another author, an opposing view). Unbadged passages are Maulana Wahiduddin Khan's own words.
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.
On the subject of al-din the Quran has this to say: He has ordained for you the same din which He enjoined on Nuh (Noah) and which We have revealed to you and which we enjoined on Ibrahim (Abraham) and Isa (Jesus) (saying): Observe this din and be not divided therein. (42:13).
On the other hand, there is another verse of the Quran which tells us that the shariat given to different prophets were not always identical. The Quran states:
We have ordained a law (Shariah) and a path for each of you. And had God so willed He would have made you all a single community, but He wanted to try you by what He had given you. Vie with each other then in good works, for to God you shall all return and he will resolve for you your differences. (5:48)
The Shariah, or external structure of the commands of Islam, and the minhaj, or method varied from prophet to prophet, but only in a partial, not a total sense. It should be borne in mind also that such differences as these were related not to individual prophets but to the changed situations. The different circumstances of the times each prophet lived in were taken into account in the commands they were given in terms of the Shariah and minhaj. These variations were based on the practical wisdom rather than related to the person of a particular prophet. That is why this principle of Shariah is valid even today.
The principle of the change in situations governing partial and temporal alterations in the Shariah and minhaj is duly adopted. While in the past this change was carried out through the Prophet, modifications are now arrived at through ijtihad and carried into effect by the Islamic scholars.
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.