What is a word for when you accept someone else's beliefs, but do not believe in them yourself?
Tolerant willing to accept feelings, habits, or beliefs that are different from your own
a culture tolerant of religious differences
If I say I am tolerant of someone's beliefs it means I accept his/her faith without prejudice. However, this does not mean I will share his/her religious convictions or views; I may even want to distance myself from them.
The antonym of tolerant is intolerant
Wikipedia has a passage which illustrates how closely related the two words are. They are, ironically, often used in unison.
Walzer, Karl Popper and John Rawls have discussed the paradox of tolerating intolerance. Walzer asks "Should we tolerate the intolerant?" He notes that most minority religious groups who are the beneficiaries of tolerance are themselves intolerant, at least in some respects. Rawls argues that an intolerant sect should be tolerated in a tolerant society unless the sect directly threatens the security of other members of the society. He links this principle to the stability of a tolerant society, in which members of an intolerant sect in a tolerant society will, over time, acquire the tolerance of the wider society.
Hypocrite. The urban dictionary actually has "hippocrite," meaning "A squishy hippo that happends to be hypocritical of others. Derived from the word hypocrite, but accomodated to specificy hippos." (http://www.urbandictionary.com/define.php?term=hippocrite). My laugh for the day. Cheers all.