1. The World in Jesus Christ (PBUH)'s View

This world is a bridge, pass it and don't get attached. 

Sheikh al-Mufid, Al-Amali, p.43.

2. You Reap What You Sow

Everyone is after the reward [that comes at the end], and no one will get it except through hard work. 

Mizan al-Hikma, hadith no. 22083.

3. The Lasting Lights

Good for the ones who pray at the heart of the night; those are the ones who will inherit a lasting light. 

Tuhaf al-Uqul, p.510.

4. Faithfulness in Jesus Christ (PBUH)'s View

A tree is perfected only through giving fruit, as faithfulness is only accomplished through avoiding what is forbidden (Haram). 

Tuhaf al-Uqul, p.511.

5. Beware of Your Eyes

Be careful about what you are looking at since the mere act of looking [at something inappropriate] will put the seed of desire in your heart, which would later turn into a disaster. 

Tuhaf al-Uqul, p.502. 

6. Most Cherished Ones

Good for the ones who make amends among people; those are the most cherished on the Day of Judgement.

 Tuhaf al-Uqul, p.501. 

7. Servants of This World

O' servants of the world! You are like a lamp that gives light to people and burns itself instead. 

Tuhaf al-Uqul, Hadith no.500324.

8. Modesty in Private and Public

As you present modesty and humbleness among people in public, be modest and humble with regard to God in private.

Tuhaf al-Uqul, Hadith no.500325.

9. A Fruitful Heart in Jesus Christ (PBUH)'s View

Verily, planting is only possible on arable land, not a barren one. Similarly, wisdom only grows in a humble and ready heart, not an arrogant and prejudiced one. 

Tuhaf al-Uqul, Hadith no.500332.

10. Practice Makes Perfect

Everyone looks upon the stars, but none finds his/her way using them, except the one who knows their places and how they work. Similarly, you will learn wisdom, but only the one who practices wisdom will be guided.

Tuhaf al-Uqul, Hadith no.500336.

11. Inappropriate Words' Echoes 

Any offensive and inappropriate word that you say today will be responded later on the Day of Judgement.

Tuhaf al-Uqul, Hadith no.500341.

12. Patience in Jesus Christ (PBUH)'s Words

Water puts the fire out, just as patience calms anger down.

Tuhaf al-Uqul, Hadith no.500347.

13. Perfect Faith as Jesus Christ (PBUH) Describes 

Water and soil are the determining factors for a good harvest, just as knowledge and manner are the keys to perfect faith. 

Tuhaf al-Uqul, Hadith no.500350.

14. Don't Be Just After this World 

The one who is only after this world is like a person drinking seawater; the more he drinks, the more he gets thirsty and finally will bring him death. 

Warram b. Abi Firas al-Hilli, Tanbih al-khawatir wa nuzhat al-nawazir, vol.1, p.149.

15. This World and The World that Is to Come

Jesus Christ (PBUH) said to the apostles: "As much as you get tired in this world, you will rest in the other world, and as much as you rest in this world, you'll get exhausted on the world that is to come."

Ismaiil Jawuhari Farabi, Al-Sahah, vol.1, p.225.

16. The Root of All Evil

Beware that the root of all evil lies in loving this world extremely. 

Warram b. Abi Firas al-Hilli, Tanbih al-khawatir wa nuzhat al-nawazir, vol.1, p.129.

17. Water and Fire

Loving this world and striving for the other world cannot come together in a believer's heart, as water and fire cannot be put together on a plate. 

Warram b. Abi Firas al-Hilli, Tanbih al-khawatir wa nuzhat al-nawazir, vol.1, p.131.

18. God's Friends 

If you want to be among God's friends and chosen ones, be kind to the one who does you wrong, and forgive the one who has done you an injustice, and greet the one who turns his face from you.

Tuhaf al-Uqul, p.503.

19. A Magnificent Person 

Whoever knows and brings what he knows into practice and teaches others, is considered a magnificent person in Allah's regard.

Warram b. Abi Firas al-Hilli, Tanbih al-khawatir wa nuzhat al-nawazir, vol.1, p.82.

20. The Most Wretched One

The most wretched among you is the one who is only known by his/her knowledge, not his/her deeds. 

Bihar al-Anvar, vol.2, p.52. 

As we all know, human life is on an extremely fast pace of progress that is made possible by human expeditions and exploration. But no one can say for sure that all the achievements of this progress have been used on the righteous path. Some of these explorations are known as a forward leap in human history just like dynamite that has been used to ease miner’s jobs. But the same invention has also been used as a deadly weapon against thousands of innocent humans. Obviously, Islam did not miss this point about human life and gave advice to all Muslims in this regard: “Islam forbids eating, drinking and consuming things that are harmful to human health. The more harmful it is, the more severe the prohibition of its cause and effect, to the extent that it reaches the level of sanctity.” (1)

Now, we are going to talk about narcotics, the basis of all of the soothing medicine that are used as one of the essential materials in the ancient times surgery but is also used by heedless people for entertainment at the expense of decomposing their body and brain.

Narcotics are the most common cause of death and disability in the world that exacerbates many diseases, including cardiovascular, pulmonary, infectious diseases, cancer, bone diseases, gastrointestinal diseases, hearing problems, and oral diseases. In every 8 seconds, one person in the world dies of diseases caused by narcotics; fortunately, with the advancement of science and technology and optimal information, the level of awareness of people about the effects of narcotics on their health has increased. We will see what advice Islam gave us on the issue of using narcotics for mortal pleasure.

The opinion of some of the leaders of Islam about Drugs

As we said before, Islam forbids consuming materials that are harmful to human health to the extent that even on some occasions it reaches the level of taboo. Imam Khomeini, the first leader of the Islamic Republic of Iran said: "Eating something that is harmful to human beings is forbidden."(1) It is obvious that the criterion for being haram (forbidden) is to have harmed, and it does not matter whether this harm goes through eating or in some other way. Drugs is one of the things that harm human health, but is it harmful to the extent that makes it forbidden to use?

Many physicians and practitioners are following the opinion that narcotics has significant harms and have written numerous books on the dangers and diseases caused by narcotics, especially smoking. Therefore, it can at least be claimed that the harmful effects of smoking to human health vary based on the person and the situation. On this basis, some jurists have considered the extent of the forbiddance of narcotics to the level of absolute religious prohibition. Some other leaders have not seen the extent of the damage to the extent that could lead to an absolute ban on smoking. For example, if a person has heart disease and his doctor strictly forbids him from smoking, smoking is forbidden for him. (2) 

Not only Imam Khomeini, but also Ayatollah* Makarem Shirazi said: It is forbidden to eat or drink something that is significantly harmful to human beings. Smoking cigarettes and other types of tobacco is also haram if it has significant harm, but the use of narcotics is absolutely haram (3), whether in the form of injection or smoking or eating or in any other ways; also the production, sale and assistance in spreading it, is forbidden. (3)

Grand Ayatollah Sistani gave guidance to Muslims in this matter: If smoking and tobacco -though in the future- causes significant harm to the body to the amount that is feared by the wise person, it is haram for being safe from the major harm caused by it. There is no problem with moderate smoking, however. (4)

Conclusion

As we think about this matter reasonably, we surely would understand an important point: 
1. Why should we harm ourselves for a little mortal entertainment?
2. What price should we pay for this kind of entertainment?

Just think and you will see how important abstaining from narcotics is. Live safely in the light of the Quran. 

References:

1. Majma Al-Masayel (third volume – page 65)
2. Islamic Laws (Second volume – page 600)
3. Jame Al-Masayel (First volume – page 578)
4. Islamic Laws (Second volume – page 600)
5. The official site of Ayatollah Sistani

* Ayatollah is an honorific title for high-ranking Twelver Shia clergy in Iran and Iraq that came into widespread usage in the 20th century.