Islam's history from the time of Prophet Muhammad (PBUH&HP) until now has witnessed many challenges that were overcome through the flexible and rational set of rules offered by Allah. The way Islam deals with the requirements of each era and how its principles and rules can be applied to new cases are among the reasons for the quick spread of Islam during ages, which are addressed in this part of the topic. 

Time and evolution in Islam's History

Islam is basically sensitive to the evolutions and the requirements of each epoch. This is not the case for many religions and sects, especially those founded by humans. Imam Ali (AS) has advised: “not to impose the customs and traditions of your time on your children because they belong to a different era from yours” [1].

Unlike other creatures of the world such as animals, plants and inanimate objects, humans have memory, tradition, and history; animals might have memory, but not tradition nor history. This makes it possible for humans to compare different periods of their life and form the concept of progression and retrogression; which is not the case for animals and plants.

And, that is the reason why the specifications and the requirements of each time become meaningful; e.g., old vs. new, classic vs. modern, etc. This makes one pause once in a while to ask him\herself: am I going forward or actually taking a step back? And undoubtedly, getting advanced would be the most pleasant reflection that one can have. But, how can one be on an ever progressive path? 

Life framework Should be Based on Wisdom

For self-development, one needs a set of values, disciplines, and rules with the help of which he\she can define a structure for his\her life that will consequently guarantee his/her success and advancement over time. This also applies to social development.

On the other hand, every human being is not able, nor has time, to contemplate every detail and strategy about life and to establish his\her framework. Hence, one usually relies on the teachings and instructions of a specific sect, religion or ideology. But, how is it possible? How can one select the best framework and then adjust it according to the specifications of each era such that it can apply to every period? That is possible with the help of wisdom. 

More Rational, Closer to human Wisdom and More Acceptable

Among various ideologies and religions known in the course of time, those who are more rational can be adapted better to the requirements of each period and are consequently more understandable and acceptable by humans. Such a religion or ideology provides the principles and rulings which can be perceived by the human’s wisdom and from which humans can conclude and extract the guidelines and codes that are exclusive to each era.  

Islam, a wisdom-based religion

Among different religions, Islam is really the only one that is rational and is based on wisdom; So are the divine guidelines. Every good act and deed ordered to is rationally and truely useful in nature, not because it is a divine order. And something known devilish in Islam is intrinsically wrong; it is not wrong because God has told us so. In other words, it is not Islam who renders something good or bad, it rather provides the rational tools to identify what is wrong and what is right. That is the reason why Islam is more compatible with the specifications of each time, i.e., it provides the axioms and frameworks and leaves the rest to the human’s wisdom. This takes place through a process called Ijtihad. 

Ijtihad and Rational Solutions to the New Cases

Using Ijtihad, Islamic jurists (Faqih) derive the guidelines and regulations from the principles of the Quran, the narrations, and traditions of Prophet Muhammad (PBUH&HP) and the Infallible Imams (AS). In this regard, Imam Sadiq (AS) said that the Infallible Imams had introduced the Islamic axioms and it is a duty over Muslims to deduce the details and rules [2].

This is the Islamic jurisprudence which is a unique characteristic that enables Islam to propose rational solutions, to respond to new issues and questions at each time. It also facilitates for human beings the application of the Islamic axioms to their activities and dealings. Otherwise, religion or ideology that is limited to the text, and has no solution to become updated in the course of time, will be a temporary time-dependent one that cannot survive through the time evolution. 

According to what has been mentioned above, Islam as a whole guide and roadmap is able to consider new situations, and issues raised at different periods and propose relevant solutions for them. Islam's history has shown it as a dynamic religion whose guidelines are not limited to the cases in a thousand years ago but meets the requirements of all time. Of course, it should be noted that being ever up to date does not mean to welcome every new change and circumstance; it rather means to derive the relevant Islamic orientation and ruling by considering the Islamic axioms.   

References:

1. Ibn Abi l-Hadid, “Comments on Nahj al Balaqa”, vol. 20, p. 267, T. 102.
2.  M. Al-Hili, "Al-Saraʼir Al-Hawi Li-Tahṛir Al-Fatawi", vol. 3, p. 575.

Hadith 21: The Condition of Honor

Imam Sadiq (as) said: Whoever wants to be in the neighborhood of the Prophet (pbuh&HP) and next to Ali (AS) and Fatima (AS) should not leave the pilgrimage of Imam Hussain (AS).  
Wasa'il al-Shi'ah, vol. 10, p. 331, p. 39

Hadith 22: Pilgrimage, Divine Duty

Imam Sadiq (as) said: If one of you observes the Ihram of Hajj for the entire of his life but does not visit Imam Hussain (as), he has left the right of the Messenger of Allah (PBUH&HP) because the right of Hussain (as) is a divine duty and obligatory for every Muslim.
 Wasa'il al-Shi'ah, vol. 10, p. 333

Hadith 23: Karbala, the Kaaba of Perfection

Imam Sadiq (as) said: Whoever does not visit the grave of Imam Hussain (as) until he dies, his faith will be incomplete and his religion will be incomplete, and when he goes to heaven, he will be lower than the believers there. 
Wasa'il al-Shi'ah, vol. 10, p. .335

Hadith 24: From Pilgrimage to Martyrdom

Imam Sadiq (as) said: Do not leave the pilgrimage of Imam Hussain (as) and recommend it to your friends and companions as well! May Allah prolong your life, increase your sustenance, and may Allah bless you alive and you will not die except as a martyr. 
Wasa'il al-Shi'ah  vol. 10, p. 335

Hadith 25: The Hadith of Love

It was narrated from Imam Sadiq (as) that he said: Whoever Allah wants good, will put the love of Hussain (AS) and his pilgrimage in his heart, and whoever Allah wants bad, will have him hate Hussain (AS) and anxious with his pilgrimage.
 Wasa'il al-Shi'ah  vol. 10, p. 388, Sea of Lights, vol. 98, p. 76

Hadith 26: A Sign of Being a Shiite

Imam Sadiq (as) said: Whoever does not visit the grave of Imam Hussain and dies as our Shiite and dies, is not our Shiite, and even if he is from the people of Paradise, he is the guest of the people of Paradise.
Kamel Al-Ziyarat, p. 193, Bihar Al-Anwar, vol. 98, p.4

Hadith 27: Ascension Platform

Imam Sadiq (as) said: Whoever visits the grave of Hussain (as) and has knowledge of the right of that Imam, Allah Almighty will register him in the highest rank.
Man la yahzurul Faqih, vol. 2, p.581

Hadith 28: The School of Knowledge

Imam Musa Kadhim (as) said: The least reward that is given to the pilgrim of Imam Hussain (as) on the banks of the Euphrates is that all his sins, before and after, are forgiven. Provided that he knows the right, honor and guardianship of that Imam.
Mustadrak al-Wasa'il, vol. 10, p. 236, quoting Kamil al-Ziyarat, p. 138

Hadith 29: Like the Pilgrimage of Allah

Imam Reza (as) said: Whoever visits the grave of Imam Hussain (as) on the banks of the Euphrates is like the one who has visited Allah. 
Mustadrak al-Wasa'il, vol. 10, p. 250, quoting in full

Chapter Three: Ashura and Arbaeen

Hadith 30: Pilgrimage at Ashura

Imam Sadiq (as) said: Whoever visits Imam Hussain (as) on the day of Ashura, heaven will be obligatory for him. 
Iqbal al-A'mal, p. 568

Hadith 31: Above Prosperity

Imam Sadiq (as) said: Whoever wakes up on the night of Ashura next to the shrine of Imam Hussain (as), on the Day of Judgment he will rush to Allah stained in his blood, like someone who was killed in Karbala next to Imam Hussain (as). 
Wasaelu shiah, vol. 10, p.372

Hadith 32: Signs of Faith

Imam Hassan Askari (as) said: The signs of a believer are five: 

1 Fifty prayers 

2 Arbaeen pilgrimage

3 Ring in the right hand 

4 Prostrating on the ground 

5 Saying loudly the name of Allah, (Bismillah Rahman Rahim)

 Wasaelu shia, vol. 10, p. 373, and also Al-Tahdhib, vol. 6, p. 52

Chapter Four: Torbat and Tasbih of Love

Hadith 33: His Porch 

The Prophet of Islam (PBUH&HP) said: Know that the answer to prayer is under the dome of his shrine and healing is in his soil, and the Imams (as) are of his children.
 Mustadrak al-Wasa'il, vol. 10, p.335

Hadith 34: Soil and Training

Imam Sadiq (as) said: Take your children with the soil of Hussain (as) (Karbala) because the soil of Karbala insures your children. 
Wasaelu Shiah, vol. 10, p.410

Hadith 35: The Greatest Medicine

Imam Sadiq (as) said: The cure for any pain is in the soil (torbat) of Hussain (as) and it is the greatest medicine. Kamil Al-Ziyarat, p. 275 and Wasa'il al-Shi'ah, vol. 10, p. 410

Hadith 36: Torbat (soil of Karbala) and seven hijabs

Imam Sadiq (as) said: Prostration on the soil of Hussain (as) tears the seven veils. 
Mesbah al-Muttahid, p. 511, and Bihar al-Anwar, vol. 98, p. 135

Hadith 37: Prostration on the Soil of Love

Imam Sadiq (as) did not prostrate on the ground except on the soil of Hussain (as) and he did this in violence for the sake of Allah.
Wasailu shiah vol. 3, p.608

Hadith 38: Rosary with the Soil of Karbala

Imam Sadiq (as) said: Prostration on the soil of Karbala can light up to the seventh earth, and whoever has a rosary from the soil of the shrine of Hussain (as) with him, is a truthful person, even if he says nothing.
Man la yahzurulFaqih vol 1 p 268 

Hadith 39: Healing Soil

Imam Kadhim (as) while narrating a hadith announcing his death, said: do not take anything from the soil of my grave to seek blessings, because it is forbidden for us to eat any soil except the soil of my grandfather Hussain (as), Allah Almighty has healed only the soil of Karbala for the Shiites and our friends. 
Jami ahadith, vol. 12, p.533

Hadith 40: One of the Four Needs

Imam Musa ibn Ja'far (as) said: Our needs are four things:

1. Prayer mat on which prayers are offered.

2. Rings on the finger

3. Toothbrush with which to brush teeth

4. A rosary from the shrine of Imam Hussain (as) Tahdhib al-Ahkam, vol. 6, p. 75