“A Hindu can not be a fundamentalist because there is nothing fundamental or obligatory in his socio-religious life, but he can be fanatic, a greater fanatic than all....”

Source: Service-Boat And Love-Boatman (1974), p. 2, Part 1
Context: Nothing can be greater than love. God is great only because He has infinite Love. If we want to define God, we can define Him in millions of ways, but I wish to say that no definition of God can be as adequate as the definition of God as all Love. When we say "God", if fear comes into our mind, then we are millions and billions of miles away from Him. When we repeat the name of God, if love comes to the fore, then our prayer, our concentration, our meditation, our contemplation are genuine.

2000s, AARP magazine interview (2008)
Context: When a life is at stake and it's your child, you become fearless in a lot of ways. I mean, you jut become fanatic. Nothing ever gets done unless it's done by a fanatic.

With regard to this fundamental principle, as we have now declared and adopted it without farther definition or limitation, this third Age is precisely similar to that which is to follow it, the fourth, or age of Reason as Science,—and by virtue of this similarity prepares the way for it. Before the tribunal of Science, too, nothing is accepted but the Conceivable. Only in the application of the principle there is this difference between the two Ages,—that the third, which we shall shortly name that of Empty Freedom, makes its fixed and previously acquired conceptions the measure of existence; while the fourth—that of Science—on the contrary, makes existence the measure, not of its acquired, but of its desiderated beliefs.
Source: The Characteristics of the Present Age (1806), p. 19

As quoted in How the Allies Won (1995) by Richard Overy, citing Hitler: The Man and the Military Leader (1972) by P.E. Schramm
Other remarks

2000s, 2008, (2008)

Light (1919), Ch. XXIII - Face To Face

Seduction (1990)
1990s

Not found in Burke's writings. Appears to be a paraphrase of "It is the greatest of all mistakes to do nothing because you can only do little." sourced to Sydney Smith (1771 - 1845).

Source: Uncle Tom's Cabin