Blessed be her holy hooves.
Religious relics! Read about The Holy Sock of Bob.
Summary of the Major Articles of Faith
Our Lady Unicorn is Pink and Invisible.
She prefers Pineapple and Ham Pizza to Pepperoni and Mushroom. The latter is said to be eaten only by followers of the despicable Purple Oyster (of Doom). [cf]
The Followers of the IPU have more Holy Days than those of all other faiths put together, as any Holy Day of any faith is automatically an IPU Holy Day. Holy Days are used by the Faithful to sow seeds of doubt and uncertainty in the minds of addicts of other religions. The Holiest Day of the Year is April 1st. It is the day on which the She suggests we find a religious nut and say "There is as much evidence for the existence of your god/gods as there is for the Invisible Pink Unicorn, why don't you check out her web-site, maybe you'll learn something?"
A significant number to followers of the IPU is 42. It is the answer to the question, "What is the meaning of life, the universe, and everything?" Importantly, if you add together the digits of the year in which she was revealed, (1+9+9+4) you get 23. If you add 4 (for Her hooves), add 2 (Her ears) add 2 (Her eyes) add 1 (Her Horn), add 1 (Her tail) then add 9 the result is also 42. This proves the significance of Two Score and Two.
Certain chosen followers of the IPU are blessed with visitations, shown with signs in their laundry. See the Revelation of The Lost Prophetess of AOL for more details.
The New Revised Amalgamated Standard Creed
We believe in One Unicorn, The Pink, The Invisible. Creator of Uncertainty, revealed to us in the alt.atheist usenet forum - She that Raptures Socks. She will smite those that mock Her brethren. Others believe baloney, we too will join the feast. We shall eat our fill, yea every belly shall be full of ham and pineapple pizza. Her Revelations show us the folly of all Religions. Spread Her Word.