As it was with Boromir (who wanted it for good) or Gandalf when he denies taking the ring.
They could've ended doing evil with initial noble intentions, that's how the ring would've exploited them.
Exactly. Galadriel, Elrond, and Faramir also have the opportunity to take the One Ring, and choose not to. Sadly Faramir's rejection of it was not portrayed in the movies.
As it was with Boromir (who wanted it for good) or Gandalf when he denies taking the ring. They could've ended doing evil with initial noble intentions, that's how the ring would've exploited them.