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. 

Allah almighty has bestowed upon us so many gifts that even if you try your hardest, you cannot count them all: 

He gave you all that you had asked Him. If you enumerate Allah’s blessings, you will not be able to count them. Indeed, man is most unfair and ungrateful! (Holy Quran, 14:34)

However, if you reflect further, you will realize that the greatest favor of Allah to us is the opportunity to use these gifts. Life is a priceless blessing that many people often overlook. We must appreciate this precious gift from Allah and use it in the best way possible. Regarding this, Allah Almighty warns us about wasting our time in the Holy Quran,

I swear by Time! * Mankind is indeed in loss, * except those who have faith and do righteous deeds, and enjoin one another to [follow] the truth, and enjoin one another to patience. (103:1-3) 

This life is short yet crucial because it’s all we have got. Allah almighty says,
On the Judgement Day, He will gather them [it will be] as if they had not remained [in the world] except for a moment of the day getting acquainted with one another. They are certainly losers who deny the encounter with Allah, and they are not guided. (10:45)

Imam Ali (AS) also states,

Your opportunities pass just like the clouds pass; therefore use the good opportunities. (1)

Those who wasted their time in this world on trivial matters will lament on the Judgement Day:

They are certainly losers who deny the encounter with Allah. When the Judgement Day overtakes them suddenly, they will say, ‘Alas for us, for what we wasted in the world!’ And they will bear their burdens on their backs. Look! Evil is what they bear! (6:31)

Giving the importance of time, Islam has set some principles to make the most efficient use of it

Avoid wasting time on unimportant things 

Many of the activities we engage in during the day are unproductive. In the Islamic view, it is crucial to understand the importance of spending time on beneficial things. Imam Sadiq (AS) says,
One of the signs of a good Muslim is that he avoids things that have nothing to do with him (2)

Self-Assessment

Imam Ali (AS) says:

It is so necessary for one to have a time during the day allocated for self-Assessment so that they could see what they have done during the day and the night that had benefit or damage for them. (3)

Imam Kazim (AS) advised his pupil Hisham:

O Hisham! He is not one of us who doesn’t assess himself every day. (4)

Set goals

Imam Ali (AS) said,

God bless the one … who sets goals. (5)

Time management

Imam Ali (AS) said,

For achieving success, manage your time, and to manage your time, think clearly, and for thinking clearly, hide your secrets. (6)

To effectively manage time the most important thing is to know how to allocate every part of our daily life for something needed. In this regard Imam Kazim (AS) says,

Try to divide your time into four parts: one for praying and talking to Allah, another for work, one for spending time with your friends and trustworthy individuals who let you know about your faults and imperfections and who sincerely love you. The last part is for your lawful pleasures and by this last part, you get ready for the other three parts. 

Don’t talk with yourself about poverty or length of lifetime. Because anyone who thinks about poverty will become miserly and anyone who thinks about the length of life will become greedy. Give yourself your share of this world by pleasing yourself with lawful things which don’t harm your character or waste your time. (7)

Think before acting

Imam Ali (AS) said:

Thinking before acting saves you from regretting. (8) 

One of the best ways to save time is to think carefully before taking any action. Some people think that acting impulsively leads to faster success. They think that overthinking is a sign of fear, so they advocate for thinking less and acting more. However, Islam doesn’t support this notion as it encourages thoughtful consideration and reflection before taking any action. 
In this regard, Imam Ali (AS) said,

Every movement requires knowledge. (9)

Imam Sadiq (AS) also said,

The one who acts without needed insight is like a passenger on the wrong road. The faster he goes, the farther he gets from his destination. (10)

The holy Prophet (PBUH & HP) said:

When you want to do something, think about its results, if it brings benefits or progress, act and if it is harmful or causes regression, refrain from doing it. (11) 

We only live this life once, but its consequences will remain in the Hereafter. Don’t squander this opportunity and by making the best of it, secure a better life for yourself in the Hereafter. 

Resources

1.  Nahj al-Balaghah, Sayyed Razi, sayings no.12
2.  Vasa’il ash-Shia, Sheikh Hurr al-Ameli, vol.12, pg.199
3. Ghorar al-Hikam, Amodi, pg.896
4.  Mustadrak al-Vasa’il, Muhaddith an-Nuri, vol.12, pg.153
5. Bihar al-Anvar, Allamah al-Majlesi, vol.75, pg.51
6.  Nahj al-Balaghah, SAyyed Razi, sayings no.84
7. Tohaf al-Uqul, Harrani, pg.409 & 410
8.  Bihar al-Anvar, Allamah al-Majlesi, vol.68, pg.337
9.  Tohaf al-Uqul, Harrani, pg.171
10.  Al-Kafi, Sheikh Koleini, vol.1, pg.43
11.  Al-Faqih, Sheikh Saduq, vol.4, pg.410 & 411