Badges mark quoted or attributed material (Qur'an, hadith, another author, an opposing view). Unbadged passages are Maulana Wahiduddin Khan's own words.
In a hadith Prophet Muhammad observed: My generation is the best one, then the second generation and then the third generation. (Sahih Muslim, 8/550)
This means that Islamic virtue was at its peak in the first generation, and that there was a decline in righteousness through the second and the third generations. This stage is known in the history of Islam as the period of the Prophet’s companions and the period of Prophet’s companions’ companions.
There is nothing mysterious about it. Degeneration, a law of nature which applies to every group, set in after the first generation itself. By the third generation, the roots of Islam had weakened and by the fourth generation the characteristics of the first generation had been considerably diluted. This process went on until after a few centuries that period commenced when, we do find individuals in considerable number who had imbibed the true spirit of Islam, but society on the whole was found drastically lacking in the features of the early Islam.
This is what is meant by Islam becoming “a stranger,” as in the above-quoted prediction of the Prophet. In latter times this difference has become so marked that the Islam of the early days has come to appear strange to the Muslims of today. Some basic reasons for this transformation are outlined below: