The Wiccan Rede ~ Short Version
Traditional:
Bide the Witches' Rede ye must, in perfect love and perfect trust. Eight words the Rede thou must fulfill: An' it harm none, do as ye will. What ye send forth returns to thee, so ever mind the rule of three. Follow this with mind and heart, and merry ye meet and merry ye part.
Modern:
Be careful what you do.
Be careful who you trust.
Do not use the Power to hurt another, for what is sent comes back.
Do not use the Power against someone who has the Power, for you draw from the same well.
To use the Power you must feel it in your heart and know it in your mind.