If that's the only aspect of puritanism you care about in a specific discussion - that is, you aren't discussing drinking, gambling, using drugs, or anything else - how about "I don't believe in casual sex"?
It's not a word a person would normally use about themself because it does have negative associations.
It doesn't make me think of the religious aspect as much as 'puritan' does so yes, I could describe Ghandi as puritanical, as a question of attitude. And not just me either:It's still Christian, though, don't you think? You wouldn't describe Gandhi or Pythagoras as puritanical, would you?
I absolutely would describe them as (lower-case) puritanical, though they were definitely not (upper-case) Puritans. Many names of religions or religious sects began as ordinary English words and can still be used that way (perhaps in a slightly different form) if the first letter is not capitalized. One can be methodical without being a Methodist, have catholic tastes without being Catholic, be reformed without being either in the Dutch Reformed Church or a Reform Jew, be conservative without being a Conservative Jew, and so on. That's why proper capitalization is important in situations like this - a difficult thing to learn for people whose native language does not make a similar distinction between two forms of the same letter.It's still Christian, though, don't yat ou think? You wouldn't describe Gandhi or Pythagoras as puritanical, would you?