“Be The Peace You Wish To See In The World!”

Transform Your Life: A Blissful Journey (2001)

Gini…Khağağutyan Hamar [Woman… For Peace] (1911)
Context: All over the world, and quite independently of each other, there is a growing wish for peace. This idea travels around the world, growing stronger all the time and becomes one irresistable and universal ideal. This is the great hope of people who are weary and dissillusioned by wars between nations and social groups. Both the victors and the defeated need an end to hostilities. [... ] Who destroys the seeds of past antagonisms in the tender mind of a child and prepares it for a bright, infinite peace of soul. It is of course the child's mother. [... ] The backbone of the feminist movement in France is formed by the women who get together to achieve peace through education and this movement also determines the direction taken by feminist movements in other countries, with their various branches and supporters

Last words, 10/16/46. Quoted in "The Mammoth Book of Eyewitness World War II" - Page 562 - by Jon E. Lewis - History - 2002

Said about Absinthe https://en.wikipedia.org/wiki/Absinthe. Quoted in “Letters to the Sphinx from Oscar Wilde: With Reminiscences of the Author" by Ada Leverson (London: Duckworth, 1930)

1900s, Inaugural Address (1905)
Context: While ever careful to refrain from wrongdoing others, we must be no less insistent that we are not wronged ourselves. We wish peace, but we wish the peace of justice, the peace of righteousness. We wish it because we think it is right and not because we are afraid. No weak nation that acts manfully and justly should ever have cause to fear us, and no strong power should ever be able to single us out as a subject for insolent aggression.

There is "no reliable documentary evidence for the quotation", according to an article in The New York Times. Brian Morton, "Falser Words Were Never Spoken" http://www.nytimes.com/2011/08/30/opinion/falser-words-were-never-spoken.html?_r=0, New York Times, 2011-08-29. It is not found as a direct Gandhi quotation in the 98-volume authorized Collected Works of Mahatma Gandhi. Misquotes that Bapu is forced to wear http://articles.timesofindia.indiatimes.com/2011-10-03/ahmedabad/30238203_1_bapu-tushar-gandhi-gandhiji
The earliest evidence for quotes of this type comes from the "Love Project", an initiative begun at 1970 at a high school in Brooklyn, New York by teacher Arleen Lorrance. According to the project's website http://www.consciousnesswork.com/love.htm, "Be the change you want to see happen, instead of trying to change anyone else" was one the principles of the Project "received" by Lorrance in 1970 -- but contemporaneous evidence for this has not been found.
A 1972 newspaper article states: "Instead of advocating change in people and things, ... Love Project encourages people to actually be change itself". [San Antonio Express, 1972-09-28, 76, 'Love Project' Marks End of Quest, Ron, Fulkerson, https://www.newspapers.com/clip/12194386/love_project_1972/]
In 1974, Lorrance wrote, in a report on the Project: "One way to start a preventative program is to be the change you want to see happen." ( "The Love Project" https://books.google.com/books?id=NcTimfiMzYUC&pg=PA85&lpg=PA85&dq=arleen+lorrance+love+project+1972&source=bl&ots=X5fggiqrCZ&sig=JoOzC2X1QU1eePkOBoy-60rJ1RE&hl=en&sa=X&ved=0ahUKEwiAwIv-_a_MAhUBW2MKHYBQDFIQ6AEIQDAH#v=onepage&q=%22be%20the%20change%22&f=false, in Kellough (ed.), Developing Priorities and a Style, MSS, 1974).
In 1976, a newspaper report listed "'Be the change you want to see happen, instead of trying to change anyone else" as one of the principles of the Love Project. 'A Ministry Called "The Love Project", St Louis Post Dispatch, 1976-11-15, p. 36
In 1987, a similar quote was attributed to Gandhi in a New Mexico newspaper: "You must be the change you wish to see in the world". Hollis Engley, "A Long List of Varied Accomplishments" https://www.newspapers.com/clip/5211946/a_long_list_of_varied_accomplishments/, The New Mexican, Santa Fe, NM, 1987-01-11, p. D-1
In 1991,"We must be the change we wish to see in the world" is attributed to Gandhi in Stella Cornelius, "Partners in Conflict Resolution", from Barnaby (ed.), Building a More Democratic United Nations (1991) Google Book link https://books.google.com/books?id=rcYYoLsFNmAC&pg=PA70&dq=%22be+the+change%22+%22wish+to+see%22&hl=en&sa=X&ved=0CB0Q6AEwAGoVChMI4ufD3tSLyQIVFFJjCh1muQX6#v=onepage&q=%22be%20the%20change%22%20%22wish%20to%20see%22&f=false
Arun Gandhi, grandson of Mahatma Gandhi, has attributed the quote to his famous grandfather since at least 2000 https://web.archive.org/web/20000823060048/http://www.jca.apc.org/g21/panelists.htm. See also "Arun Gandhi Shares the Mahatma's Message" by Michel W. Potts, in India - West [San Leandro, California] Vol. XXVII, No. 13 (1 February 2002) p. A34, and "Be the change you wish to see: An interview with Arun Gandhi" by Carmella B'Hahn, Reclaiming Children and Youth [Bloomington] Vol. 10, No. 1 (Spring 2001) p. 6.< It is not clear whether Arun claims to have directly witnessed his grandfather saying it, or whether he heard of it second-hand.
Misattributed

Last words as quoted in The Execution of Nazi War Criminals (1946) by Kingsbury Smith of the International News Service