10 Welcome Changes Deep Space Nine Made To The Star Trek Formula
3. Strong Religious Themes
This was one of the things that Gene Roddenberry expressly wanted to avoid in his perfect Star Trek vision. And indeed, TOS and TNG are largely devoid of anything overtly religious. As far as humans are concerned, science and religion are, more often than not, mortal enemies - at least, in the real world. But other species have quite a different approach.
As discovered in the show's very first episode, there exist a group of mysterious, vastly powerful alien lifeforms that appear in visions to select individuals they deem worthy. The people of Bajor believe these beings to be 'Prophets' and worship them as gods. Major Kira is especially passionate about her faith, which often brings her into conflict with the religious leader of Bajor, Kai Winn.
What makes her religion so impactful is that it is shown to have kept her going during the Cardassian occupation of her home planet when she was a child. In the face of such brutality, she held onto her beliefs, giving her the strength to endure when her parents were cruelly snatched away from her.