That entire conversation was very interesting. Here's a transcript:
LOCKE: She loved me. If I had just... [sighs] we could've been together.
ABADDON: Maybe you could have. That wouldn't change anything. She'd still be gone.
LOCKE: Would she?
ABADDON: Helen is where she's supposed to be. As sad as it is, her path led here. And your path, no matter what you did or what you do, your path leads back to the Island.
LOCKE: You say that like it's all det--inevitable.
ABADDON: Mr. Widmore told me Richard Alpert said that you were going to die. So you tell me, John. Is that inevitable, or is it a choice?
LOCKE: What, you think I wanna die? How is that... how could you possibly think that's a choice?
ABADDON: Hey... I'm just your driver.
The prime of the conversation seems to go back to the entire faith vs science aspect of the show. Is everything determined or are you given choices along the way?
It is somewhat similar to Desmond's visions about Charlie. Desmond could have kept saving Charlie over and over, but it was inevitable that Charlie would die. And in the end, Charlie made the choice to die to save everyone else.