Montag's belief in his work, his understanding of the power of his position as a fireman, and the knowledge that he was providing a service to the community are all depicted in this quote.  

"It was a pleasure to burn. It was a special pleasure to see things eaten, to see things blackened and changed. With the brass nozzle in his fists, with this great python spitting its venomous kerosene upon the world, the blood pounded in his head, and his hands were the hands of some amazing conductor playing all the symphonies of blazing and burning to bring down the tatters and charcoal ruins of history." (Bradbury) 

Montag's joy and pleasure in watching the process unfold, the unleashing of the great flame, the power it possess to crush and destroy to eliminate, wipe away, reduce to ashes and dust that which stood before it, was intoxicating to Montag and it gave him a sense of great power.

Montag enjoys his power, which really is based on his obedience to the state, as long as his base of knowledge remains committed to the state, he will remain powerful.  Once he decides that knowledge is a tool that provides opportunities for free thought, he is in trouble.  

In Fahrenheit 451, the power base is conformity, in one's sameness there is power as Montag's fireman experiences.  Once he decides to transform into an individual capable of free thoughts outside the state's belief system and rules, he becomes a rogue, a wanted man, an outlaw, his power is reduced but his knowledge is increased.  Knowledge in this book is really dangerous.

Of course in this novel the knowledge that gives power comes from books, which is why the firemen are so keen on burning every book they can come across. Two key quotes that explore the reasons for this policy are as follows:

Do you know why books such as this are so important? Because they have quality. And what does the word quality mean? To me it means texture. This book has pores.

This quote is said by Faber to Montag to justify why books are so important. To Faber, books contain quality - and more importantly, "texture", which we can take to mean authentic experience. Books contain that essential human experience of reality and emotions which the contemporary entertainment of the shells that people put in their ears and the screens simulate in a false and dumbed-down fashion. People need to have quality information, the time to digest it and the ability to act on what they have read.

We must all be alike. Not everyone born free and equal, as the constitution says, but everyone made equal . . . A book is a loaded gun in the house next door. Burn it. Take the shot from the weapon. Breach man's mind.

This quote is said by Beatty to Montag at the end of his review of the history that has brought about the existence of the firemen and the book burning policy. Beatty from this quote associates books with making man un-alike - the thoughts, ideas and themes contained in books allow man the opportunity to be different, to disagree, which runs counter to the philosphy of the government. Of course, Beatty's whole speech is rather ironic which makes us question his position, for he is happy to use his loaded gun to manipulate Montag.