The essence of Al Imam Al Hussein (a.s) job is to apply the words of truth and continue its path. It is about being courageous against all of the powers that faced him in this path. This is the essence and truth of Al Imam Al Hussein's job. All of the issues related to Al Imam Al Hussein, in Al Madina, in Makkah, in Karbala, during his path and all of the problems mentioned after his martyrdom were mentioned by Al Imam Al Sajjad and Zeinab (peace be upon them). All of this sheds light on this point. This is the great lesson provided by Al Imam Al Hussein (a.s).
Who are those who were against Al Imam (a.s) on that day? We should say: the whole world has enclosed him because the Yezid regime has dominated the islamic world and somehow controlled every person in accordance with him. Some were controlled with threats, others with desires and promises, and some with deception. All of those were opponents of Al Imam Al Hussein (a.s).
So does every opponent don't love Al Imam? No, they loved him! In addition, Al Imam Al Hussein used to live with respect in the Madina and whenever he went to pilgrimage (Hajj), people gathered to see him. But the issue was different. Al Imam considered the social regime of the world is not an Islamic regime at the time when the prophet Mohammad (pbuh) came to make the social regime an islamic one.
The Prophet of Islam came and created this Islamic system. However, when Imam Hussein (a.s) oneday saw the Islamic world and system are becoming completely different from Islam, and in many ways they would become 100% hostile to Islam, he decided to restore that situation.
Al Imam Al Hussein wanted to announce for all of the people during his era and the coming ones that whenever such a system is absent, a revolution should take place to have it whether it results in having a government and victory or with martyrdom.
Some people assume that if Al Imam Al Hussein (a.s) knew that he’s gonna die, he wouldn't revolt. Others assume that he revolted to be a martyr. But both opinions are wrong.
Al Imam has revolted to teach the humanity a lesson: whenever muslims (who learn from A Imam Al Hussein) see oppression in society, feel the absence of the islamic regime, the absence of Quran lead, dominance of descrimination, arrogance, abstraction of rights, and leading without a value, they should revolt to get back the right lead, whether the movement ends with a result or not.
Al Imam Al Khomaini has mentioned many times that we don’t revolt to get a result, but we revolt becasue of duty and commitment. But there is no doubt that when our revolution originates from a sincere feeling, God almighty will make our movement end with a good result.
This is the essence of the work of Al Imam Al Hussein (a.s). That’s why he held out and stayed stable for it. In reality, if a man wants to look at the day of the revolution of Al Imam according to normal values, he will surely find that unlogic. Of course, if a person wants to look from the perspective of the ordinary and natural mind, he will see that a person who does not have any strength in the face of these forces, will inevitably end in a real military defeat. However, despite that, Al Imam Al Hussein (a.s) revolted although it was easier for him to perceive matters and facts than many other people. It is certain that these details were also in front of the sight of Abi Abdul but he revolted to do the duty and achieve the divine victory, not just the military victory. But of course, if Al Imam had a military victory, he would accept it.
Lessons of Ashura, Al Maaref Islamic and Cultural Institution
 Al-Futuh,part 5, p 23, guidance, part 2, p 35-36, Beginning and End, part 8, p.151, Bihar al-Anwar, part 44, p 332.
 Imam newspaper, part 61, p 284.
 In the morning parade ceremony of the guards at the headquarters of Firouzeh Palace 2/7/1364 A.M. - 9/24/1986 AD.