The renunciation and self-sacrifice of these Quakers is a rebellion against the age.
From the guardian.co.uk
In a more cynical context, ascetic may connote some form of self-mortification, ritual punishment of the body or harsh renunciation of pleasure.
From the en.wikipedia.org
The mysticism of Christianity, created buildings with a mysterious gloom which made men more ready to submit to the renunciation of self.
From the en.wikipedia.org
In response, the Lenten fast and practices of self-renunciation were required annually of all Christians, both to show solidarity with the catechumens, and for their own spiritual benefit.