The concept of responsibility in Islam includes a wide range of matters. Human beings have certain responsibilities in Islam toward others and themselves. All creatures in this universe are naturally inclined to move toward the perfection considered for each of them. They are created in the most proper form, then, have been provided with the conditions and requirements that God has planned (20:50).

Nonetheless, none of them knows neither the path that they should pave nor the final target; except humans. According to the Quran, human beings are created for specific reasons (23:115), and they have duties and responsibilities (75:36). The most prominent responsibility in Islam that one has is towards God, as explained in the first part of the article. He\she is also responsible towards him\herself. This category of duties is discussed here.

The Rights that One Has Over Him\herself as His/her Responsibility in Islam

According to Imam Sajjad (AS), the duties of every human being towards him\herself are to serve only God by all his\her capabilities and every part of the body; and, to respect the rights of each part of the body [1]. Hence, the responsibilities in Islam of every human being towards him\herself can be divided into spiritual and physical items.

Responsibility in Islam towards the Soul

According to the Quran, God breathed into the human being of His [created] soul after he was proportioned (38:72). This makes the human’s soul of great value in Islam. Accordingly, every individual has certain responsibilities towards his\her valuable soul. These duties can be summarized in one sentence: to utilize the soul in the way of God.

That is to apply all spiritual capacities in the obedience to God and to do what brings bout God’s satisfaction. This requires one to keep the soul alive and pure by practicing what is ordered to or invited to in Islamic teachings like prayer (Salat), fasting (Sawm), pilgrimage (Hajj), etc., also by preventing any harm to the soul such as anxiety, depression, etc. 

The Rights that the Parts of the Body Have and One's Responsibility in Islam toward them

One’s acts and words form and determine the his\her path in life. He\she does various acts (including good deeds, what is obligatory (Wajib) or recommended (Mustahab)) with different parts of the body and verbally thank God (in the form of prayer) with the help of tongue and mouth. Hence, whatever one does concerning the obedience of God depends also on the parts of the his\her body. Therefore, he\she has some responsibilities towards them.

The Rights of the Tongue

Of the rights of the tongue are to [1]:

Avoid foul language and the sins that one might commit with the tongue, such as backbiting (ghibah) and slander. Prophet Muhammad (PBUH) said that: “Do not insult others, this turns them into your enemies” [2], and: “Whoever divulges the flaws and faults of another Muslim, God will reveal his flaws” [3]; 
Accustom it to saying pleasant beneficial words;
Force it to talk nicely and politely (2:83);
Stop it from talking too much and stay silent unless talking is beneficial; “Silence is a door to wisdom, it brings affection and guides to every blessing.” [4], and: "whoever believes in God and the Hereafter should say beneficial words, otherwise stays silent.” [5];
Think about what you are going to say and judge the words before you start talking because a wise person will be judged by his words; “A faithful person … thinks about his words first, and then says those words” [6].

The Rights of the Ears

The ears are like the doors to the heart; they transfer every word with either a positive or negative influence on the heart [1]. Imam Ali (AS) has prevented us from listening to the words without any advantage and benefit as they darken the heart and cause us to be blamed [7]. For example, whoever listens to backbiting is a partner of the backbiter [8]. Hence, one should control the ears to hear only nice and useful words that purify the heart or encourage good behavior [1]. 

To be continued. 

References:

1. Imam Sajjad (AS), Treatise On Rights (Risalat al-Huquq).
2. M. al-Kulaynī, “Al-Kafi”, vol. 2, p. 360.
3. Al-Monzeri, “Invitation and Intimidation”, vol. 2, p. 239.
4. M. al-Kulaynī, “Al-Kafi”, vol. 2, p. 113.
5. M. al-Kulaynī, “Al-Kafi”, Introduction, p. 6.
6. W. al.Hilli, “Tanbih al-khawatir wa nuzhat al-nawazir”, vol. 1, p. 106.
7. “Ghurar Al-Hikam Wa Durar Al-Kalim”, T. 6234.
8.  A. Saberi Yazdi, “Al-Hokm Al-Zahera”, p. 558.
    

As explained in the first part of the topic, Islam has spread much more quickly compared to other religions all over the world. The traits of Prophet Muhammad (PBUH&HP) were introduced as one of the reasons. Here, the effect of the scientific and social interactions with the rest of the world throughout the Islam's history is discussed. 

 As an introduction, it is good to know that Islam has adopted two types of regulations; confirmed rules and established ones. The Islamic approach regarding the confirmed rules -the regulations which existed before and were conserved or revised if needed- is one of the keys to the development and permanence of Islam. And, this will be the focus of this article.   

Saying Yes to the Good Costumes throughout Islam's History

The Islamic approach to the habits and rules that were common in the pre-Islamic era was that it neither opposed them totally nor accepted them entirely. In some cases, Islam has affirmed and preserved some rules. That was when those rules or customs were not in contradiction to the social order and the living facilities of humans or in case of the righteous customs and traditions that existed before the emergence of Islam; e.g., some of the rules on making contracts. 

However, some of the useful regulations required to be revised and this was accomplished by adding some conditions. On the contrary, some customs and routines were opposed and removed due to the bugs and disadvantages or because they were manipulated or misused for personal benefits; e.g., usury (Riba) [1].

The rules conserved by Islam, such as those about the ownership and property, are called confirmed rules. On the other hand, the rules instituted by the Islamic jurisprudence which never existed before are called established rules [1]. This demonstrates that Islam has always been in constant interaction with the world, and the positive aspects of human societies are considered. Hence, the message of Islam and its framework have not been far from what people are familiar. This consequently has made it easier to accept Islam.

Seeking knowledge; A Way to Spread Islam

Islam has urged everyone to seek knowledge. The first verse of the Quran revealed to Prophet Muhammad (PBUH&HP) enjoined reading which is the key to knowledge: “Read in the Name of your Lord who created” (96:1). Literacy and having knowledge are so important in Islam that Quran equals illiteracy to being in darkness. According to Prophet Muhammad (PBUH&HP), seeking knowledge is obligatory (Wajib) for every Muslim and God loves those who seek knowledge [2].

Learning and seeking knowledge have been emphasized such that Muslims have been encouraged even to travel in order to learn things. Imam Ali (AS) recommended traveling to acquire privilege and named gaining knowledge as one of the achievements of traveling [3]. Prophet Muhammad (PBUH) advised seeking knowledge even if for that purpose one should go to the lands far away [4].

The Holy Quran also addresses the believers as those who are not affected by the wrong behaviors of others since they have been guided. So, the believers can peacefully learn from the positive aspects of others. Another proof of the attention paid to knowledge in Islam is that Muslims used to release the prisoners of wars who taught literacy to a certain number of Muslims. All these emphases and recommendations have urged Muslims to travel to gain knowledge. As a result, Muslims who traveled to other places and countries were practically the messengers of Islam there, which, in consequence, accelerated the spread of Islam.

Continuous interaction with the world During Islam's History 

The actual advances all over the world are the outcomes of the efforts that various nations and civilizations have made in the course of time, among which are the Islamic civilizations [6]. Muslims in different countries, like Spain and Italy, have always been in interaction with other people; therefore, they could transfer the Islamic civilization and culture to others and also receive from them. As an instance, in the battle of the Trench (Khandaq), Salman Farsi proposed to dig a trench around Medina.

This was a tested strategy in Persia, and Prophet Muhammad (PBUH&HP) accepted it. Many of the important Arabic resources and books were translated into European languages, some of which were later on taught and used as references in scientific centers in non-Muslim countries. The bonds between Muslims and Christians through marriage [i] and social relationships were of other means to expose non-Muslims to Islam [7]. All these factors have helped the quick spread of Islam.

From what has been discussed, we can see that the Islamic approach of making regulations under the form of confirmed rules, the encouragement to obtain knowledge and literacy, and cultural exchanges with the rest of the world played significant roles in attracting many savants and people to the religion of Islam.    

Notes:
[i] This kind of marriage named Interreligious marriage is permitted in Islam under the certain conditions. 

References:

1. spreading Islam
2. “Misbah al-Shariah”, p. 13.
3. M. Nuri, “Mustadrak al Wasail”, vol. 18, p. 115.
4. “Misbah al-Shariah”.
5. “Ghurar al-Hikam wa Durar al-Kalim”, p. 46, T. 188.
6. history of Islam
7. A. Velayati, “Dynamism of Islamic and Iranian Culture and Civilization”, vol. 1.