The Golden Rule in 20 World Religions

1- Hinduism:

"This is the sum of Dharma [duty]: Do naught unto others which would cause you pain if done to you." (Mahabharata, 5:1517)

2- Buddhism:

"Hurt not others in ways that you yourself would find hurtful." (Udana-Varga, 5:18)

3- Jainism:

"A man should wander about treating all creatures as he himself would be treated." (Sutrakritanga, 1.11.33)
4- Tamil Tradition:
"Do not do to others what you know has hurt yourself." (Tirukkuṛaḷ, Tiruvalluvar,  Chapter 32, k. 316)

5- Taoism:

"Regard your neighbor’s gain as your gain, and your neighbor’s loss as your own loss." (Tai Shang Kan Yin P’ien, 213-21)

6- Confucianism:

“What I do not wish men to do to me, I also wish not to do to men." (Analects, 15:23)

7- Shinto:

"The heart of the person before you is a mirror. See there your own form." (Munetada Kurozumi, Opening Way, 57)

8- Zoroastrianism:

"Whatever is disagreeable to yourself do not do unto others." (Shayast-na-Shayast, 13:29)

9- Judaism: 

"...thou shalt love thy neighbor as thyself." (Leviticus, 19:18)

10- Ancient Greece:

"What you do not want to happen to you, do not do it yourself either." (Sentences of Sextus, 179)

11- Ancient Rome

"What you would avoid suffering yourself, seek not to impose on others." (Epictetus, Fragment 38)

12- Christianity: 

"And as ye would that men should do to you, do ye also to them likewise." (Luke, 6:31)

13- Islam:

"None of you [truly] believes until he wishes for his brother what he wishes for himself." (Al-Nawawi's Forty Hadiths, 13)

14- Sikhism:

"As you deem yourself, deem others as well; only then will you become a partner in heaven." (Guru Granth Sahib, p.480)

15- Sufism:

"Human beings are members of a whole, In creation of one essence and soul. If one member is afflicted with pain, Other members uneasy will remain. If you have no sympathy for human pain, The name of human you cannot retain." (Saadi, Gulistan, 1, 10)

16- Ancient Incas:

"Do not to another what you would not yourself experience." (Manco Capac, Testament, 11)

17- Native American:

"May all these people and all their generations walk together as relatives." (Black Elk, Sacred Pipe, 37)

18- Ancient Egyptian:

"Do for one who may do for you, that you may cause him thus to do." (The Tale of the Eloquent Peasant, 109 - 110)

19- The Yorubas of West Africa:

"He who injures another injures himself." (The Juvenile, vol.1, 176, 1853)

20- Moroccan tribesmen:

"What you desire for yourself you should desire for others." (Wit and Wisdom in Morocco, Westermarck, 236)  
21-Theosophy

"Therefore, we say, that unless every man is brought to understand and accept as an axiomatic truth that by wronging one man we wrong not only ourselves but the whole of humanity in the long run, no brotherly feelings such as preached by all the great Reformers, pre-eminently by Buddha and Jesus, are possible on earth." (Blavatsky, The Key to Theosophy, 47)

thanks to http://www.religioustolerance.org/reciproc2.htm