All Abrahamic religions believe in the return of the savior, the liberator of the human beings and redeemer, in the End-Time. Prophets and divine messengers have promised the day that the whole universe will be full of justice and tenderness. Other religions also have similar beliefs, although they differ in some minor aspects, which will be discussed below. We go through references from different religions and faiths to examine their views about the last savior. 

Kalki: The Last Savior in Hinduism

In Upanishads, which is a collection of ancient Sanskrit texts that contain some of the central philosophical concepts and ideas of Hinduism, the last savior is called Kalki. He is believed to be the tenth avatar of Hindu god Vishnu in the last of the four stages in the endless cycle of existence known as "Samsara," which is defined "as the endless cycle of birth, death, and rebirth. Or as the world of suffering and dissatisfaction (dukkha)" [1].  He rides a white horse with a fiery sword. He will end the darkest and destructive period to remove adharma [i] and will usher in the Satya Yuga [ii][2]. 

Another reference talks about a just commander at the end-time who is the leader of angels and humans, who knows the truth and gets hold of everything from deep in the seas too high in the mountains, and no one greater than him will come to earth [3].

Saoshyant: The Eschatological Savior in Zoroastrianism

In Zoroastrianism, there are three saviors who each will rise in a thousand years. The last one is an eschatological savior figure who will destroy evil and will bring about the renovation of the world. He is called Saoshyant, which means the beneficent in its single form. Yet, in its plural form, it is considered to mean the redeemer. The Khorda Avesta describes this savior as such:

Whose name will be the victorious SAOSHYANT and whose name will be Astvat-ereta. He will be SAOSHYANT (the Beneficent One) because he will benefit the whole bodily world; he will be ASTVAT-ERETA (he who makes the bodily creatures rise up), because as a bodily creature and as a living creature he will stand against the destruction of the bodily creatures, to withstand the Druj of the two-footed brood, to withstand the evil done by the faithful. [4]
Accordingly, the Soashyant will rise at the end-time and fight against the vices in the world and spread justice and goodness far and wide. 

Maitreya: The Future Buddha

In some of the Buddhist references, such as the Amitabha Sutra and the Lotus Sutra, we read about the future Buddha of this world, called Maitreya, who will be a successor to the present Buddha. In Sanskrit, Maitreya means kindness and love. According to Buddhist religious texts, Maitreya will be the fifth and last Buddha who will appear on the earth. The arrival of Maitreya is expected at a time in the future when the dharma will have been forgotten by most on the earth. That is when Maitreya will appear on the earth to achieve complete enlightenment and to teach the pure dharma [5].

Li Hong: The Last Savior in Taoism

The Taoist last savior, called Li Hong, is depicted as an ideal leader who would reappear to set right heaven (tian) and earth (dì) at a time of upheaval and chaos. Li Hong will appear at the end of the world cycle to rescue the chosen people, who would be distinguished by certain talismans, practices, and virtues [6].

Savior in Abrahamic Religions

Moshiach: The Last Savior in Judaism

The Jews belief in the savior is manifested in the idea of the coming of Moshiach (i.e., Messiah). This person is believed to be a descendant of King David, who will "gather the Jews from all over the world and bring them back to the land of Israel" [7]. There are many verses in different scriptures and Talmudic [iii] literature which refer to this figure and enumerate his characteristics and manners [iv]. For instance, Isaiah says:

And there shall come forth a rod from the stock of Jesse [King David's father], and a branch shall grow from his roots; and the spirit of the Lord shall rest upon him, the spirit of wisdom and understanding, the spirit of counsel and might, the spirit of knowledge and of the fear of the Lord. And his delight shall be in fear of the Lord; and he shall not judge by what his eyes see, nor decide by what his ears hear. But with righteousness shall he judge the poor, and decide with equity for the humble of the earth; and he shall strike the earth with the rod of his mouth, and with the breath of his lips shall he slay the wicked.
–Isaiah 11:1-4

Those who follow Judaism believe that their savior has not been born yet. Therefore, they are eagerly awaiting the coming of the one who will save them and establish a just dominion in which "there will be world peace, no more wars nor famine, and, in general, a high standard of living" [7]. 

The Messiah: Jesus Christ (PBUH) the Savior of Mankind 

Christians believe that Jesus Christ (PBUH) is himself the savior of humankind, and he was born for this purpose. The name Christ literally means "the anointed one" or the Messiah [8]. As the Gospel of Matthew says, Jesus Christ (PBUH) has been sent to "Save his people from their sins" (1:20-21). It is also believed that Jesus Christ (PBUH) had been crucified to atone the sins of humanity and lead them toward salvation. According to Christian sources, Jesus Christ (PBUH) was the savior who was awaited by the Jews as whose coming was predicted in the Torah as the Moshiach. 

Another point which makes Jesus Christ (PBUH) the awaited savior in Christianity is the idea of his second coming or the Second Advent in the end-time to whose "day or hour no one knows, not even the angels in heaven, nor the Son, but only the Father" (Mark 13:32). This is the belief in "the future return of Christ in glory when it is understood that he will set up his kingdom, judge his enemies, and reward the faithful, living and dead" [9]. Different gospels, including Matthew chapters 24–25; Mark, chapter 13; Luke, chapter 21:5–26, and John, chapter 14:25–29, are mentioned as the evidence for this belief. Moreover, according to biblical verses, there will be many signs indicating the end-time among which the second coming of Jesus Christ (PBUH) and the last judgment. 

Therefore, like many other religions, Christians also believe in a savior or as they call it the Messiah, who will make this world a better place and free it from oppression and injustice. 

Imam Mahdi (AS): The Awaited Savior in Islam

In Islam, the belief in the savior is rooted in the fact that Allah never leaves His creatures, especially human beings, on their own and support them through sending His apostles to guide them toward the right path: "and there is a guide for every people" Quran (13:7). He had sent 124000 prophets (PBUT) first, followed by righteous leaders who continued the path of previously chosen messengers of Allah. As the Quran says, "Certainly We wrote in the Psalms, after the Torah: 'Indeed My righteous servants shall inherit the earth.'" (21:105).

 Therefore, the earth will never become empty of Allah's guide, and people will benefit from these guiding lights either directly or indirectly. Imam Mahdi (AS), the twelfth leader of Muslims and a descendant of Prophet Muhammad (PBUH&HP), who is leading a secret life at the time, will ultimately rise and spread peace and humanity throughout the earth. "The Holy Prophet (PBUH&HP) informed Muslims about his reappearance, telling his names, attributes, appellations, and peculiarities" [10]. The time of his coming is unknown, and it is followed by the preparation of particular circumstances. 

The signs that indicate his coming include "Widespread injustice and oppression, the advent of Dajjal (Anti-Christ) who would misguide the thinking of the people, the advent of Sufyani who is one of the pillars of mischief and corruption on the earth, the formation of the Islamic army, which would raise up black standards, the voice of the angel of the sky giving glad-tidings of his reappearance, the coming down on earth of Jesus Christ (PBUH) and his paying allegiance to and praying behind in congregation Prayers led by Imam Mahdi (AS)" [11]

This belief in the last savior, who would stand against tyranny and injustice and remind human beings of their real value, also, highlights Islam's optimism toward the future of the world.

Finally, we have reviewed the belief in the last savior or the person who will save humankind from the evilness and destruction in this world in different faiths and religions. On a more in-depth look, we can find many similarities between these beliefs. However, the Abrahamic religions had a more precise and more tangible attitude toward the idea of the last savior and the time of his coming. Therefore, the concept of the savior is one of the most essential and significant matters regarding the future of human destiny. 

Notes:
[i] Opposite to dharma, which includes unnaturalness, wrongness, evil, immorality, wickedness, and vice. 
[ii] The period when humanity will be governed by gods and every manifestation or work is close to the purest ideal, and humanity will allow intrinsic goodness to rule supreme.
[iii] The central text of Judaism and the primary source of the Jewish religion. 
[iv] Isaiah 2, 11, 42; 59:20, Jeremiah 23, 30, 33; 48:47; 49:39, Ezekiel 38:16, Hosea 3:4-3:5, Micah 4, Zephaniah 3:9, Zechariah 14:9, Daniel 10:14. 

References:

1. Samsara
2. the man on the white horse
3. The Vishnu Purana, trans. Horace Hayman Wilson, London: Trübner & co., Book IV, Chapter 24.
4. Khorda Avesta, Translated by James Darmesteter (From Sacred Books of the East, American Edition, 1898.), Part five
5. Buddhism
6. Anna K. Seidel. "Perfect Ruler in Early Taoist Messianism: Lao-tzu and Li Hung." History of Religions, Vol. 9, No. 2/3
7. The end of days
8. what does christ mean
9. second coming
10. Sayyid Ali al-Husayni al-Milani, The Promised Savior: An inquiry into the imamate of Imam Mahdi (as) from the viewpoint of Muslim thinkers, part 1, p.8. 
11. Baqir Shareef al-Qurashi, The Life of Imam al-Mahdi, Trans. Sayyid Athar Husayn S.H. Rizvi, p.259-283. Pdf. 

1. Speak at the Right Time

Don’t speak when it’s not a good time to talk. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no. 10274. 

2. A Day of Celebration

Any day on which you don’t commit sins or disobey Allah is a day of celebration (Eid). 

Nahj al-Balagha, Wisdom no.428. 

3. The Effect of Nature 

Looking at nature brings happiness.

Nahj al-Balagha, Wisdom no.400. 

4. Two Valuable Blessings in Imam Ali (AS)'s Words 

There are two things whose worth you will find out only after losing them; youth and health.

Ghurar al-Hikam wa Durar al-Kalim, vol. 1, p.449.

5. Difference with Children 

Do not impose your own traditions on your children, since they are living in a different era than yours. 

Ibn abi al-Hadid, Interpretation of Nahj al-Balagha, vol.20, p.286. 

6. Who to Consult and Who not to Consult

Consult with your wise enemy, but avoid your ignorant friend’s advice. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.2471.

7. The Best Candidates to Consult

The wise, knowledgeable, experienced, and prudent ones are the best to consult with. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.4990.

8. When to Consult 

Consult before making decisions and think before taking action.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.5754.

9. Be Patient with Your Job's Difficulties 

If you don’t endure the difficulties of working, you are made to bear the misfortunes of poverty.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.8987.

 10. Be Kind

Be kind to the less privileged ones than you, so that your superiors be kind to you. 

Muhammadi Reyshahri, Mizan al-Hikmah, Hadith no. 6960. 

11. Respect Your Father and Teacher

Rise in respect to your father and your teacher, even if you possess a high status. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.2341.

12. The Foundation of the World according to Imam Ali (AS)

The world is founded on justice. 

Muhammadi Reyshahri, Mizan al-Hikmah, Hadith no. 11955. 

13. Observe Justice 

The fairest among you is the one who observes justice between people while in power.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.3242.

14. Treat others as you expect to be treated

The fairest manner is to treat people the way you expect them to treat you. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.3170.

15. Quality is more important than Quantity for Imam Ali (AS)

Don’t worry about how fast you do a job; instead, observe the best quality in whatever you do. 

Ibn abi al-Hadid, Interpretation of Nahj al-Balagha, vol.20, p.267. 

16. The Worst Homeland

The worst homeland is the one that doesn’t keep its citizens safe. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.5712.

17. How to Start a Deed

You need to have enough knowledge of a deed before doing it. 

Nahj al-Bakagha, p.171.  

18. Do Every Deed on its Own Time 

Do every day’s work on that specific day, since each task is due to its special day. 

Nahj al-Balagha, letter no.53.  

19. Keep Your Promises

The ones who don’t keep their promise do not believe in Allah. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.9577.

20. Don't Break Your Promise to Children 

It’s beneath you to make a promise to your child and not keep it. 

Al-Shaykh al-Saduq, Al-Amali, p.342. 

21. Be Childlike 

If you have a child, be childlike with him/her. 

Usul al-Kafi, vol.6, p.50. 

22. Yesterday, Tomorrow, Today 

Yesterday is gone, tomorrow is yet to come, while today is a precious chance for you to make the most of it.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.9840.

23. An Unplanted Land

The heart of the teenage is like an unplanted land that is ready to receive any seed planted in it. 

Nahj al-Balagha, letter no. 31. 

24. Read Books

The greatest peace is obtained by reading books. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.8126.

25. Scholars' Heaven 

Find the scholars’ heaven within the pages of the books. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.991.

26. The Perfection of Religion

The perfection of religion is in seeking knowledge and making use of it. 

Usul al-Kafi, vol.1, p.30.

27. What is Said not Who Said it 

Pay attention to what is said, not who is saying it. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.5048.

28. Think instead of Talking

Try to ponder and understand instead of quoting. 

Muhammadi Reyshahri, Mizan al-Hikmah, Hadith no. 3355.

29. Help Others

You will be helped, the same way as you help others. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.7209.

30. The Faithful as Defined by Imam Ali (AS)

The faithful who help the destitute in the hardships and misfortunes of their lives are loved most by Allah.

Tuhaf al-Uqul, p.376.

31. Peace is Better Than War

I found peace, so far as it won’t degrade Islam, more beneficial than war. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.10138.

32. You Make a Mistake, too!

Don’t be happy about the mistakes of others, since you are not perfect either. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.10294.

33. Respect to be Respected 

Talk respectfully to people to hear respectful responses. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.2568.

34. The Power of Optimism 

Optimism reduces despair and keeps you away from committing sins. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.4823.

 35. Do not Measure Truth Based on People 

What is right is not distinguished by the people; You should first know what is right to find the ones following it.

al-Fattal al-Neyshaburi, Rawḍat al-wāʿiẓīn wa baṣīrat al-muttaʿiẓīn, p.31.

36. Be at Peace

Whoever avoids holding grudges, his/her heart and mind will remain at peace. 

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.8548.

37. Be Thankful and Patient 

Be thankful to Allah on your days of comfort and happiness, and be patient on the days of difficulty and hardship.

Ghurar al-Hikam wa Durar al-Kalim, Hadith no.7148.

38. The Precious Blessing of Health 

Health is more precious than any other of Allah’s blessings. 

Ghurar al-Hikam wa Durar al-Kalim, p.483.

39. Women in Islam

Women are Allah’s trusts upon you, do not hurt them, and do not put pressure on them.

Mustadrak al-Wasail, vol.2, p.551.

40. Make the most of Your Happy Moments 

Enjoy your moments of happiness with all your heart to help you at the time of sadness. 

Ibn abi al-Hadid, Interpretation of Nahj al-Balagha, vol.20, p.286.