The World Council of Churches (WCC), an international Christian ecumenical organization, recently released a free PDF, Love To Share, that explores the role Christianity and the church play in relation to intellectual property. Love To Share is released under a CC BY-NC-ND license and contains some incredibly well-written text that explains our licenses and how they intersect with the goals of the WCC:

[T]he present copyright legal system tends to emphasize the protection of an author/creator’s work rather than promoting a “bridge” to let ideas flow […] Creative Commons licences give you the ability to dictate how others may exercise your copyright rights, such as the right of others to copy your work, make derivative works or adaptations of your work, to distribute your work and/or make money from your work. They do not give you the ability to restrict anything that is otherwise permitted by exceptions or limitations to copyright—including, importantly, fair use or fair dealing—nor do they give you the ability to control anything that is not protected by copyright law, such as facts and ideas.

Creative Commons licences are attached to the work and authorize everyone who comes in contact with the work to use it consistent with the licence. This means that if Bob has a copy of your Creative Commons-licensed work, Bob can give a copy to Carol and Carol will be authorized to use the work consistent with the Creative Commons licence. You then have a licence agreement separately with both Bob and Carol.