While religious beliefs and practices vary widely around the world, there is near unanimity among religions, ethical systems, and philosophies that each person should be treated as we all wish to be treated. Here are examples of passages from holy texts and the words of religious leaders that promote the ethic of reciprocity (commonly referred to as the Golden Rule).
"And if thine eyes be turned towards justice, choose thou for thy neighbor that which thou choosest for thyself."
—Baha'i Faith, from Epistle to the Son of the Wolf
"Hurt not others in ways that you yourself would find hurtful."
—Buddhism, from the Udana-Varga 5:18
"And as ye would that men should do to you, do ye also to them likewise."
—Christianity, from Matthew 7:12, King James' version
"Do not do to others what you do not want them to do to you."
—Confucianism, from Analects 15:23
"Do not do to others what would cause pain if done to you."
—Hinduism, from Mahabharata 5:1517
"None of you [truly] believes until he wishes for his brother what he wishes for himself."
—Islam, from Number 13 of Imam Al-Nawawi's Forty Hadiths
"Thou shalt love thy neighbor as thyself."
—Judaism, Leviticus 19:18
"Regard your neighbor's gain as your own gain, and your neighbor's loss as your own loss."
—Taoism, words of T'ai Shang Kan Ying P'ien
"An' it harm no one, do what thou wilt."
—Wiccan, the Wiccan Recede which governs all behavior
"Whatever is disagreeable to yourself do not do unto others."
—Zoroastrianism, from Shayast-na-Shayast 13:29