Ja’far ibn Muhammad (AS) known as the Ja’far as-Sadiq (AS) is the sixth Shiite Imam. Imam Sadiq (AS) was born on 17 Rabi al-Avval 83th (702 CE) in Medina. His father, the previous Imam, was named Muhammad al-Baqir (AS) and his mother was called Umi-Farvah. After his father, Imam Sadiq (AS) became the Imam of the Shias and his leadership lasted for about 34 years. The era of Imam Sadiq (AS) was the time of instability and wars, since the Umayyad dynasty were weakened so much due to the battles they had in the Islamic territory. In addition , Abbasid dynasty were trying to topple the Umayyad government and reign over the whole Islamic world. The weakness of the rulers gave Imam Baqir (AS) and Imam Sadiq (AS) a perfect opportunity to spread the teachings of Shiism and train so many Shia scholars. At last, Imam Sadiq (AS) was martyred by the order of the Mansur (an Abbasid Caliph) on 148 H (765 CE). 

What does “Sadiq” mean?

The word “Sadiq” means an honest person who does not tell lies. 
Once, Imam Sajjad (AS), the grandfather of Imam Sadiq (AS) was asked: “Who is the Imam after you?”
“My son Muhammad (AS) who opens knowledge and after him his son Jafar who is called in the skies as ‘Sadiq’” Imam Sajjad (AS) replied. 
He was asked once more: “Why out of you all, he is called “Sadiq” while you all are honest?”
Imam Sajjad (AS) said: “Because the Prophet (PBUH & HP) said: ‘Name my son Jafar ibn Muhammd as “Sadiq” because there will be another Jafar in the future who falsely claims to be an Imam and he is named “liar” by Allah’” (On the contrary, Jafar ibn Muhammad is honest because he is a true Imam). (1)
The liar Jafar mentioned in the hadith is the son of Imam Hadi (AS), the eleventh Imam. 

The knowledge of Imam Sadiq (AS)

All Shiite Imams were known for their abundant knowledge in their time; but among all, Imam Baqir (AS) and Imam Sadiq (AS) were different. Due to the fact that Umayyad dynasty were weak and unstable in those times, Imam Baqir (AS) and Imam Sadiq (AS) had this chance to unveil the abundant knowledge of the Prophet’s household. 
About 4000 people learned from Imam Sadiq (AS) and narrated hadiths from him . (2)
Amr ibn Abi al-Mighdam, a Sunni scholar, says: 
“Every time I looked at the face of Jafar ibn Muhammad (AS), it would make me sure that he is a descendant of the prophets. Once, I saw him in Jamrah (a place in Mecca where the pilgrims gather) and he was telling people: ‘Ask me! Ask me!’” (3)
Hassan ibn Ali al-Vasha, a Shiite hadith narrator, says:
I saw about 900 sheikhs who all would narrate hadiths from Jafar ibn Muhammad (AS) (4).
Once Abu Hanifah, one of the most knowledgeable and popular Imams of the Sunnis, was asked: “Who do you think is the most knowledgeable person in religious fields?” he said: “I do not know anyone more knowledgeable than Jafar ibn Muhammad (AS)” (5).
Imam Sadiq (AS) is mostly known for his knowledge in Islamic laws and because of this, the Shiite school of law is called “Jafari School”. The hadiths narrated from Imam Baqir (AS) and Imam Sadiq (AS) are more than all the hadiths narrated from the Prophet (PBUH & HP) and the other Imams all combined together.

The moral attributes of Imam Sadiq (AS)

In addition to his wisdom and knowledge, Imam Sadiq (AS) was also known for his significant moral qualities. 
Muhammad ibn Talha says: 
“Imam Sadiq (AS) was the greatest person among the Prophet’s household and he was so knowledgeable and he would pray and recite the Quran so much and he was an ascetic person.” (6)
Malik ibn Anass, one of the Sunni school’s head, says: 
Every time I met him, he was in one of these three moods: either praying, fasting or whispering prayers (7).
Hisham ibn Salim, a famous apprentice of Imam Sadiq (AS) says:
Abu-Abdillah (Imam Sadiq (AS)) would always take a bag full of bread, meat and money in the darkness of the nights and go to the house of the needy ones in Medina and give it to them while they didn’t know him. Then, when he died, the people weren’t given those goods anymore and from that, they found out about his identity. (8)

Resources 

1.  Al-Khara’ij, ar-Ravandi, vol.1, pg.268
2.   Al-Irshad, Sheikh Mufid, vol.2, pg.179
3.    Siar A’lam an-Nubalah, Zahabi, vol.6, pg.257
4.    Rijal al-Kashi, vol.1, pg.138-139
5.   Siar A’lam an-Nubalah, Zahabi, vol.6, pg.257
6.    Kash al-Qummah, Irbeli, vol.2, pg.691
7.  Bihar al-Anvar, Majlesi, vol.47, pg.16
8.   Kafi, Koleini, vol.4, pg.8
    

Globally, the word “jihad” may be one of the scariest words associated with Islam in people’s view. Terrorism and Islam are almost intertwined when people talk about this religion. When you talk about Islam, many people may think of ISIS, Al-Qaida, Taliban, and the like which have portrayed an internationally terrifying picture of Muslims. On the other hand, most Muslims believe that the real Islam and the original meaning of “jihad” have been defamed by these terrorist groups. 

What does jihad mean?

The word “jihad” denotes an attempt and trying. In Islam, this word means doing as Allah commands in a special way that mostly requires hard work and sacrifice for his sake. It would be quite wrong merely assume fighting and killing enemies as the meaning of “jihad.” As a matter of fact, this word has a lot of meanings and “fighting” is only one of them. 

According to the Holy Quran, jihad can be waged even without fighting enemies, but by spending your wealth on the needy.

The faithful are only those who have attained faith in Allah and His Apostle and then have never doubted, and who wage jihad with their possessions and their lives in the way of Allah. It is they who are truthful.  (49:15)

The Holy Quran says that the Meccan early Muslims who left all they had in Mecca and moved to Yathrib (today called Medina) had done “jihad,”

Indeed, those who are faithful and those who have migrated and waged jihad in the way of Allah—it is they who expect Allah’s mercy, and Allah is all-forgiving, all-merciful. (2:218)

Sometimes the word jihad means fighting not with the enemies but with yourself. In Islamic insight, controlling your evil and harmful desires is actually considered to be an example of jihad. Surprisingly, this kind of jihad is actually more important and nobler than the other types. In this regard, Imam Sadiq (AS) says,

Once, the Holy Prophet (PBUH & HP) sent a group of soldiers to the battlefield, and when they came back, the Prophet (PUBH & HP) told them, ‘welcome to the people who accomplished their little jihad and still have to do the greater jihad.’

 People asked, ‘Oh, Messenger of Allah! What is the greater jihad?’ 

He replied, ‘fighting with yourselves.’ (1) 

Was the Prophet eager to wage wars?

In Islam’s view, fighting is originally only for defending ourselves against invaders not for attacking innocent people. 

The first fight of the Prophet (PUBH & HP) named “Badr”, was with the Quraysh (the people of Mecca who were mostly the Prophet’s relatives). After Muslims moved to Medina from Mecca, the polytheists seized all of their belongings and were planning to sell them. A large number of soldiers escorted the caravan that was moving the belongings of Muslims from Mecca. Muslims decided to fight with them and take their belongings back. 

There was a polytheist named Utbah ibn Rabi’ah who wasn’t sure whether to fight with the Prophet. He talked to his army, riding a red camel, Oh, my people! Hear me out and do not fight this man and his followers. [if you worry about being called chicken hearts for not fighting] consider this shame on me and tell others that I was scared. You have so many close relatives among them and if you fight, so many of them will be killed and you, afterward, will have to live with the ones who have killed your fathers and brothers and it will leave animosity and a grudge among you. Note that if you kill them, they will kill as many of us as we have killed them. Furthermore, it is possible that you lose… Oh, my people! If Muhammad is a liar, the wolves of the desert will remove him and if he is a king, you will have a good life in his territory and if he is a real prophet, he will make you the happiest people in the world. (2)
The Prophet was so hopeful that they will listen to Utbah and that he won’t be forced to fight with his relatives. About Utbah the Prophet said, If there was only one good person among them, it would be this person on the red camel and they will do their best if they listen to him. (3)

Then, the Prophet wrote a letter to the Quraysh and encouraged them to go back to Mecca (4) but they didn’t accept and fought against the Prophet. The Muslims won this battle. 

The Arabs before the Prophet (PBUH & HP), were always fighting with each other. But, the message of Islam made them all like brothers. The Holy Quran says,

Hold fast, all together, to Allah’s cord, and do not be divided [into sects]. Remember Allah’s blessing upon you when you were enemies, then He brought your hearts together, so you became brothers with His blessing. (3:103)

Does jihad mean invading?

If you carefully read the verses of the Quran about fighting and jihad, you would understand that in the Islamic view, Muslims only fight for defending or against the ones who betray Muslims; for example, those who put the Muslim lives in jeopardy by helping their enemies.

In this regard, the Holy Quran says,

Fight in the way of Allah those who fight you, but do not transgress. Indeed, Allah does not like transgressors. (2:190)

About some polytheists who betrayed the Prophet (PBUH & HP) by violating the items of a treaty between the Prophet (PBUH & HP) and them, the Holy Quran says,

How can such polytheists have a treaty with Allah and His Messenger, except those you have made a treaty with at the Sacred Mosque? So, as long as they are true to you, be true to them. Indeed, Allah loves those who are mindful ˹of Him˺. How? For if they get the better of you, they will observe toward you neither kinship nor covenant. They please you with their mouths while their hearts spurn you, and most of them are transgressors. (9:7&8)

Therefore, the holy Quran ordered the Prophet (PBUH & HP) to forget about the treaty and fight with those polytheists because they betrayed the Muslims. 

 Muslims are eager to have peace with others but yet they can’t stand to be oppressed, invaded, bullied, etc. Fight them until persecution is no more, and religion becomes [exclusively] for Allah. Then if they desist, there shall be no reprisal except against the wrongdoers. (2:193)

Muslims believe that instead of fighting, people must be united in worshipping Allah which is the common belief of Muslims, Jews, and Christians. So, Muslims do not want to fight with the Jews or Christians except if they invade first. The Holy Quran says,

Say, ‘O People of the Book (Christians and Jews)! Come to a common word between us and you: that we will worship no one but Allah, that we will not ascribe any partner to Him, and that some of us will not take some others as lords besides Allah.’ But if they turn away, say, ‘Be witnesses that we have submitted [to Allah].’ (3:64)

The Holy Quran says that we should always be fair, even with our enemies,

O believers! Stand firm for Allah and bear true testimony. Do not let the hatred of a people lead you to injustice. Be just! That is closer to righteousness. And be mindful of Allah. Surely Allah is All-Aware of what you do.  (5:8)
And, If any of those idolaters seek your protection, protect him so that he will be able to hear the words of God. Take him to a place where he is safe because they are people who do not know the truth. (9:6)
About the wars of the Prophet (PBUH & HP), Imam Sadiq (AS) said,

The Prophet (PBUH & HP) told his soldiers, “…do not over-kill and do not cheat them and do not cut their bodies into parts and do not kill the elders, kids, or women and do not cut the trees except if you had no choice. And if any of the Muslims saw one of the polytheists, that polytheist shouldn’t be harmed until he hears the words of Allah. If he obeyed you then he is your brother and if he didn’t, then take him to a safe place [and let him go]. (5) 

Resources

1.  Al-Kafi, Shiekh Koleini, vol.5, pg.12
2.   Maghazi, al-Vaghedi, vol.1, pg.63
3.   Maghazi, al-Vaghedi, vol.1, pg.60
4.   Maghazi, al-Vaghedi, vol.1, pg.61
5.  Vasa’il ash-Shia, Sheikh Hurr al-Ameli, vol.15, pg.58