Islam has spread much more quickly than the other religions all over the world. The question is how this has happened? And it becomes more important when we consider the situation in which Prophet Muhammad (PBUH&HP) emerged.

He (PBUH&HP) invited people to Islam while he did not have any wealth or position and even when his family opposed him; except his wife, Lady Khadija (AS), and his cousin, Imam Ali (AS). Several factors were involved which we will discuss in a series of articles. Here, the focus is on how pleasant characteristics of Prophet Muhammad (PBUH&HP) helped Islam to become well known throughout the world.

The Quran confirms the impact of Prophet Muhammad’s (PBUH&HP) behavior 

In the Quran it is emphasized that the morals and attitude of Prophet Muhammad (PBUH) was one of the factors which attracted people to Islam: “had you been harsh and hard-hearted, they (people) would have surely scattered from around you” (3:159). This pleasant behavior of the Prophet (PBUH&HP) which made people inclined to him and Islam is known to be due to the God’s mercy over him (PBUH&HP) (3:159).

Indulgent in Personal Affairs, Severe in People’s Rights

Prophet Muhammad (PBUH&HP) was forgiving towards those who had bothered him or even insulted him. It is narrated that once, a Jew accused Prophet (PBUHHP) of owing him some money and insisted on paying him back immediately. Prophet (PBUH&HP) told him gently that he had made a mistake, but the man repeated his claim and suddenly assaulted the Prophet (PBUH&HP). The companions of Prophet (PBUH&HP) came to interfere, but he (PBUH&HP) said: “I know how to deal with my friend.” He (PBUH&HP) behaved very nicely such that the man acknowledged that this behavior is only expected from a prophet and he declared his belief and embraced Islam right there. 

However, he (PBUH&HP) was very serious about applying Islamic regulations or others’ rights. It is narrated that a woman from Quraysh [i] had stolen something; she confessed and had to be punished. Many people, including her family, interfered to change the Prophet’s mind and to stop her punishment. Prophet (PBUH) told people that they had meddled because she was from a famous family, but there is no exception to Islamic rules. 

Taking Advice from Others

To provide an exemplary leader for others, to train people to act alike, to valorize his companions and to convince people to follow his instructions, Prophet (PBUH) used to take advice. Of course, in the end, he (PBUH&HP) was the one who decided and made firm decisions: “consult them on the matter. And when you have decided, then rely upon Allah” (3:159).

Advertising and Inviting to Islam with Wisdom and Affection by Prophet Muhammad (PBUH&HP)

“Invite (mankind) to the Way of your Lord with wisdom and fair preaching, and argue with them in a way that is better” (16:125). Unlike what is advertised against Islam, Prophet Muhammad (PBUHHP) never forced people or threatened them to accept Islam.

On the contrary, following the advice of the Quran, he promoted Islam with kindness, fairness, and wisdom. Instead of humiliating and discriminating non-Muslims, or being harsh and fierce, he used rational argument and discussion which also improved their rationality and thinking power [1]. This followed the fact that embracing Islam should be according to the personal perception and understanding and it cannot be based on the imitation [2].

Notes:
[i]A mercantile tribe that historically inhabited and controlled Mecca and Ka'aba.

References:

1. Spreading Islam 

Life is a journey full of twists and turns. Without a guide in this deceptive path, one can become lost, forfeiting something that cannot be regained - the precious gift of redemption. That is why Islam emphasizes the need for Muslims to never be without a leader. Prophet Mohammad (PBUH&HP) is the best example of a Muslim within Islam.

There has certainly been for you in the Messenger of Allah an excellent pattern for anyone whose hope is in Allah and the Last Day and [who] remembers Allah often. (The Holy Quran 33:21)

O you who have faith! Obey Allah and His Apostle, and do not turn away from him while you hear [him]. (The Holy Quran 8:20)

These Quranic verses firmly establish that no one surpasses Prophet (PBUH&HP) as the ideal role model, guiding us to emulate his actions and lifestyle for our salvation. When we follow someone as a model in our life, we inherently respect his beliefs and ideas. 

From this, we deduce that if our model is devoted to Islam, religion, and the path of Allah's pleasure, we will also try to align ourselves with that path and potentially attain spiritual ascension. Our model here is not an ordinary person but our dear Prophet. Therefore, there is no disputing the goodwill of this revered figure. An important thing that we must learn from the Prophet (PBUH&HP) as the supreme model for Muslims is to know whom to love and whom to dislike.

The question is: how does understanding Prophet’s feelings towards individuals would help us? 
The answer lies in this: “By following the Prophet as an example, we can accurately discern these people, subsequently progressing toward Allah’s satisfaction and eternal happiness.” 

Two figures whom the Prophet constantly favored were Imam Hassan and Imam Hussein (as). Imam Hussein (AS) was born on the third of Sha'ban in the fourth year of AH.

Since the great Prophet passing in the tenth year of AH, Imam Hassan and Imam Hussein (AS) spent their childhood with their dear grandfather.

Before delving further, let us know more about our third Imam. Imam Hussein (as) is also called Aba-Abdillah and Sayyid al-Shuhada among the Shias. He is the third Imam for the Shias, martyred in the course of Ashura. He is the second child of Imam Ali (AS) and Fatemeh Zahra (AS), and the grandson of Prophet Mohammad (PBUH&HP). Following his brother Imam Hassan’s (AS) leadership, he took charge of leading the Shias for ten years. Both Shia and Sunni historical records confirm that the Prophet of Islam (PBUH&HP) announced his martyrdom at his birth and chose the name "Hussein" for him. (1)

The Prophet held deep affection for Imam Hassan and Imam Hussein and recommended everyone to love them. Imam Hussein (AS) is one of the of Prophet’s Ahl al-Bayt and also one of the recipients of the verse of purification*.

Numerous narrations from Prophet Mohammad (PBUH&HP) extol Imam Hussain’s virtue. A famous narration quotes the Prophet (PBUH&HP) on Imam Hussain (AS): “Hussain is from me and I am from Hussain. Allah loves who loves Hussain.” (2)

Through this narration, the Holy Prophet (PBUH&HP) show other Muslims the sacred position of Imam Hussein (PBUH) and imparts the exceptional stature of this lineage. In an era where falsehood and hypocrisy infiltrate the Muslim community, this saying compels believers to rid themselves of hypocrisy and misguidance. 

Regrettably, despite its resonance, this profound message did not deter the brutal martyrdom of Sayyid al-Shuhada (PBUH), which transpired in the Karbala before thousands of seemingly Muslim individuals.

The Prophet’s (PBUH&HP) adoration for Imam Hussein (AS) served a dual purpose: it conveyed not only his love for his grandson, but also aimed to engender affection towards Imam Hussein as the Imam of the Ummah, rallying people to follow him. Therefore, the Holy Prophet of Islam consistently introduced the Imam Ali, Fatima Zahra, Imam Hassan and Imam Hussein (AS) as his family and Ahl al-Bayt. He equated them with the Quran on numerous occasions,  underscoring the necessity for Muslims to accept their leadership and guidance for spiritual elevation. The Prophet also said this in the hadith of the thaqalayn: 

"Indeed, I am leaving two things among you, to which if you hold yourself, you will never astray: the book of Allah –who is almighty and great- and my Ahl al-Bayt (household), my 'itra (family). O people hear! And I have announced to you that indeed you will enter my presence and I will ask you about what you did to the thaqalayn (two weighty things) and the thaqalayn are the book of Allah and my Ahl al-Bayt."(3)

Conclusion: 

These narrations illuminate Imam Hussein’s (AS) lofty status in the the Prophet’s (PBUH&HP)eyes and the Prophet’s responses to him serves as a guide. Not only are Muslims, as followers of the Holy Prophet, must praise and love Imam Hussein, but we must also adopt his behavior, thoughts, and ethics, and follow his path in our lives. Furthermore, the Prophet's interactions with Imam Hussein underscore that those who harbor hostility or animosity towards him today are not true Muslims. This group should not be regarded as part  of the Prophet’s (PBUH&HP) religion.

References:

1.  Al‑Irshad (2nd Volume - page 130)
2.  Sunan al-Termizi (6th volume – number 3775)
3.  Al-Kafi (1st Volume – page 452)

----------------------
*The Verse of Purification is the 33rd verse of Al-Aḥzāb in the Quran (33:33). The verse has special importance for Shia Muslims due to giving information about Ahl al-Bayt of Prophet Muhammad (PBUH&HP). Shias reportedly believe it to designate the "Ahl al-Bayt" being infallible.