Question

even though the revolt of 1857 did not succeed it taught the Indians and important lesson explain

Answer 1

the revolt of 1857 made them realise that they have to work together with unity and harmony to win against the British...

Answer 2

The revolt was not properly organised. The leaders of the first war of Independence did not coordinate their efforts at any stage. There was no unity among the freedom already given a very good overview of primary factors leading to the failure of the War of 1857. As such, there's not much for me to add here though I'd like to point out one important thing in case of the militaries involved.

A very important point in Age of Enlightenment warfare- or any warfare- is the necessity to maintain discipline. This especially became important during the age of gunpowder as it led to increasing importance for logistical & numerical superiority. While in earlier times, the sheer discipline & professionalism of 'warrior classes' would lead to the founding of smaller- but more disciplined- armies, it was no longer true once armies started being stuffed with levies..