Reverend Justin Welby, the head of the Anglican church, will baptise Prince William and Kate's baby at the Chapel Royal at St James's Palace in London tomorrow.
"All babies are unbelievably special, not only royal babies," he said in a You Tube film released by his Lambeth Palace headquarters ahead of the event.
"As a nation we're celebrating the birth of someone who in due course will be the head of state. That's extraordinary. It gives you this sense of forward looking, of the forwardness of history as well as the backwardness of history, and what a gift to have this new life and to look forward," he added.
His 45-minute christening ceremony will be an intimate affair, attended only by close family and friends including great-grandmother Queen Elizabeth II.
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"One of the things I'm sure about is that the Duke and Duchess of Cambridge, Prince George's parents, have had so much advice that they could probably fill a house with it.
My message to them would be, what a treat, what an amazing gift, what wonderful times that you will have. There will be great times and tough times, as there always are with children," Rev Welby said.
The chapel has a personal connection for both parents, as William's mother, Princess Diana, lay at rest there before her funeral in 1997 and the chapel was where the Duchess of Cambridge was confirmed into the Anglican church before the royal wedding two years ago.
"Prince George will be the head of state of numerous countries around the world, he will visit more countries than most of us will ever do, and in all of them there will be those who, like him, have been baptised," the archbishop said.
The baby prince will be christened in a replica of the intricate lace and satin christening gown made for Queen Victoria's eldest daughter, Victoria, the Princess Royal, in 1841.
Following the christening, a picture will be released showing the Queen with three future monarchs - her eldest son Prince Charles, eldest grandson Prince William and great-grandson Prince George. The Royal Mint will also create a set of commemorative coins to mark the occasion.