The Holy Quran is replete with examples of men who stood for the truth and those who opposed it. The former sacrificed everything they had to defend the truth and the latter was ready to destroy everything around them to satiate their greed and selfishness.

The Book of Allah invites us to reflect upon personalities, nations, and events of the past. Whether it is pure men like Prophet Ibrahim (AS), Prophet Musa (AS) and Prophet Isa (AS) or evil men who opposed them and their mission like Nimrood, Firon (Pharoah), or Bani Israil, all of them have a lesson for us. These are not just stories to read and move on, they contain messages for our lives. And rightly so, we read in the Holy Quran:
"There is certainly a moral in their accounts for those who possess intellect. This [Quran] is not a fabricated discourse; rather, it is a confirmation of what was [revealed] before it, and an elaboration of all things, and a guidance and mercy for a people who have faith. (12:111)

Similarly, Imam Ali (AS) says: Learn lessons from past events for future events, because they are similar to one another. (Nahjul Balagha Letter 69)
One such incident of the past that changed the history of Islam forever, is the event of Karbala. No mention of Karbala is complete without Hurr ibn Yazid Ar-Riyahi. He is an example for those who reflect upon his journey, his actions and his martyrdom. He encourages, inspires and motivates the believers through his actions in Karbala. 

Background

Hurr literally means a freeman in Arabic, and truly so he lived up to his name. 
Hurr Ibn Yazid Ar-Riyahi was the general of the Ummayad army dispatched from Kufa, (Iraq) to intercept Imam Al-Hussain (AS), the third infallible Imam. Ubaydullah ibn Ziyad, the newly appointed governor of Kufa issued the command to guard all entrances and exits to Kufa in order to intercept al-Hussain for an oath of allegiance to Yazid. Hurr was ordered along with his 1,000 soldiers to intercept Imam Hussain(AS) and his followers before they reached Kufa.

When he intercepted Imam Hussain (AS) at Dhu Hussam, Hurr and his men had ran out of water. The Imam(AS) ordered his companions to satiate Hurr and his army, including the cavalry. Hurr and his men offered their prayers with the Imam and listened to his sermons. However, on subsequent orders from the tyrant governor of Kufa, Ubaidullah Ibn Ziyad, Imam Hussain and his family were forced to encamp in Karbala. Hurr was of the notion that the Imam (AS) will not be killed in Karbala, he would somehow persuade him to go elsewhere. But he was perturbed when he realized that Umar Ibn Sa'ad who was sent by Ubaidullah had come with orders to kill Imam Hussain. On one hand was his position, family and wealth and on the other hand was the grandson of the Holy Prophet(PBUH&HP) and the son of Imam Ali (AS) and Lady Fatima (SA), supporting whom meant a certain death. These were the two options left for Hurr, just as the Holy Quran says:
 "Indeed We have guided him to the way, be he grateful or ungrateful." (76:3). 

What do we learn from Hurr?

Despite all odds, Hurr left the Army of Yazid, joined Imam Hussain (AS) and won the honor of being the first martyr of Karbala. All the glitter of the world, his power, rank, wealth and children did not stop him from joining his master Hussain(AS). 
Ashura and Karbala were not be bound by time or geographical location. Almost 14 centuries have passes by but human beings from different parts of the world, belonging to different races and religions continue to mourn for Imam Hussain(AS) and take inspiration from him and his mission.
Just as Karbala continues to inspire us, the magnanimous personality of Hurr continues to inspire and guide us. Hurr chose good over bad, truth over falsehood, hereafter over the transient world. If we claim to be followers and lovers of Imam Hussain(AS) we need to turn towards the Hussain of our time and follow the teachings of Imam Hussain(AS). Imam Hussain(AS) gave everything he had to protect and preserve the teachings of Islam and by helping Hussain(AS) in his cause, Hurr achieved this lofty position of being Imam Hussain's(AS) helper. Thus, if Hurr truly motivates us, we need to mend our ways and make ourselves capable of helping Imam Mahdi (AJ) the true inheritor of Imam Hussain's (AS) legacy.

The Hurr of Karbala teaches us that true love is incomplete without sacrifice. 

But, is the Hurr inside us ready to listen?

References

1. A Probe into the History of Ashura, Ibrahim Ayati
    

Love and kindness are two of the main components of Islam. To the extent that Allah regards Prophet Muhammad (PBUH&HP) as kind and benevolent towards people of all nations in the Holy Quran: “We did not send you but as a mercy to all the nations (21:107).” And says that if he had not been gentle to people, they would have surely scattered from around him. (3:159)

Imam Hussain (AS), following in his grandfather’s footsteps, also placed particular emphasis on this prophetic trait and ethic. He was not only gentle and affectionate towards his children, family, and relatives, but also showed great care, compassion, and respect towards others, even his enemies. The whole Fifty-seven years of Imam Hussain (AS)’s life are replete with such exemplary behavior. He did not give up this attitude towards others even in the hardest situations, like when he was at war with his enemies in the desert of Karbala.

Here we will see only a few examples of Imam Hussain’s (AS) love and affection towards others in the last days of his life: 

Imam Hussain (AS)'s Attention to Children:

During the battle, in Karbala, Imam Hussain (AS) would sympathize with his family and children and treated them with love and care whenever possible. 

Imam Hussain (AS)'s Attention and Respect towards His Companions:

At the night before Ashura, Imam Hussain (AS) refers to his relatives and companions as the best ones ever: “It is a fact that I am not aware of any companions more faithful and honest than my companions and any relatives more righteous and kind than my relatives.” Imam Hussain (AS) then permits all his companions to leave him without any restrictions to save their lives, but they don’t accept. On several occasions, such as the morning of Ashura, he addresses them with the most respectful titles like “the nobles.” Also, it is narrated that during the battle, Imam (AS) would be present near his martyred companions himself, and wept and prayed for them one by one, even for the African slave, Jawn.

Imam Hussain (AS)'s Compassion for His Enemy:

Imam Hussain (AS) never used foul language or even one wrong word against his enemy. He would not hesitate to take advantage of any opportunity to stop the violence and invite his enemies to peace. For instance, when Imam Hussain (AS) and his companions came across Hur, and his army, who were supposed to intercept Imam Hussain (AS) outside Kufa, Imam Hussain (AS) quenched their thirst. He, along with his companions, also even gave water to their horses.

Another example of Imam Hussain’s compassion for the enemy is his encounter with Umar ibn Sa’ad and the other commanders of the enemy’s army on the day of Ashura, and his effort to persuade them to stop the war. In fact, Imam (AS) did not want them to commit an unforgivable sin- i.e., killing the innocent Imam (AS) and his companions- that would make them end up in hell.

So, it was only Imam Hussain's (AS) love and mercy towards humankind that touched every one’s heart, even his enemy to the extent that some of whom, like Hur, would surrender to righteousness, accompany Imam Hussain (AS), perform their prayer in congregation behind him, fight against his enemy and finally be martyred along with him. 

This is Imam Hussain’s (AS) lesson of tolerance and benevolence towards all human beings, which is beyond any religion or sect; that if one does not want to follow a particular religion, he/she can at least live a human life [3].

References:

1.  Imams sermon 
2. last night in Karbala
3. Bihar al-Anwar, vol. 45, p. 49