“I am a fanatic lover of liberty, considering it as the unique condition under which intelligence, dignity and human happiness can develop and grow;”

"Federalism, Socialism, Anti-Theologism" http://www.marxists.org/reference/archive/bakunin/works/various/reasons-of-state.htm (Fédéralisme, socialisme et antithéologisme), presented originally as a Reasoned Proposal to the Central Committee of the League for Peace and Freedom, at the League's first congress held in Geneva (September 1867)
"Reasoned Proposal to the Central Committee of the League for Peace and Freedom" also known as "Federalism, Socialism, Anti-Theologism" (September 1867)
Context: Unity is the great goal toward which humanity moves irresistibly. But it becomes fatal, destructive of the intelligence, the dignity, the well-being of individuals and peoples whenever it is formed without regard to liberty, either by violent means or under the authority of any theological, metaphysical, political, or even economic idea. That patriotism which tends toward unity without regard to liberty is an evil patriotism, always disastrous to the popular and real interests of the country it claims to exalt and serve. Often, without wishing to be so, it is a friend of reaction – an enemy of the revolution, i. e., the emancipation of nations and men.

Spongia adversus aspergines Hutteni (1523), § 176, As quoted in Desiderius Erasmus of Rotterdam (1900) by Ephraim Emerton, p. 377
Variant: I am a lover of liberty. I cannot and will not serve parties.

Amoureux et jaloux de la liberté humaine, et la considérant comme la condition absolue de tout ce que nous adorons et respectons dans l'humanité, je retourne la phrase de Voltaire, et je dis : Si Dieu existait réellement, il faudrait le faire disparaître.
Source: God and the State (1871; publ. 1882), Ch. II; Variants or variant translations of this statement have also been attributed to Bakunin:
The first revolt is against the supreme tyranny of theology, of the phantom of God. As long as we have a master in heaven, we will be slaves on earth.
A boss in Heaven is the best excuse for a boss on earth, therefore If God did exist, he would have to be abolished.

Letter to General James Longstreet (29 October 1867), as quoted in Recollections and Letters of General Robert E. Lee (1924), p. 269.
1860s

Source: Present Status of the Philosophy of Law and of Rights (1926), Ch. VII, Natural Right, p. 68.

As quoted Quote in Justice and Democracy (1997), edit., Ron Bontekoe and Marietta Stepaniants, University of Hawai’i Press, p. 233.
1930s

Address to the Society for Psychical Research (1897)
Context: The human creature represents the most perfect thinking and acting machine yet evolved on this earth, developing through countless ages in strict harmony with the surrounding conditions of temperature, atmosphere, light, and gravitation. The profound modifications in the human frame, which any important alteration in either of these factors would occasion, are strangely unconsidered. It is true there have been questionings as to the effects that might be occasioned by changes in temperature and atmospheric composition, but possible variations in gravitation seem almost to have escaped notice. The human body, which long experience and habit have taught us to consider in its highest development as the perfection of beauty and grace — "formed in the image of God " — is entirely conditioned by the strength of gravitation on this globe. So far as has been possible to ascertain, the intensity of gravity has not varied appreciably within those geologic ages covering the existence of animated thinking beings.

"The California Question" (10 June 1850), as quoted in The Selected Works of Thaddeus Stevens http://books.google.com/books?id=A0Fs655TKfsC&printsec=frontcover&source=gbs_ge_summary_r&cad=0#v=onepage&q&f=false.
1850s
Context: There can be no fanatics in the cause of genuine liberty. Fanaticism is excessive zeal. There may be, and have been fanatics in false religion – in the bloody religions of the heathen. There are fanatics in superstition. But there can be no fanatic, however warm their zeal, in the true religion, even although you sell your goods and bestow your money on the poor, and go on and follow your Master. There may, and every hour shows around me, fanatics in the cause of false liberty – that infamous liberty which justifies human bondage, that liberty whose ‘corner-stone is slavery.’ But there can be no fanaticism however high the enthusiasm, in the cause of rational, universal liberty – the liberty of the Declaration of Independence.