Something raised some flags for me when I began to think about it. Check it out...
When Locke built the sweat lodge in S3 to receive "Further Instructions," we see him go on a vision quest with Boone at the Sydney airport. A few things Boone said got me thinking...
BOONE: John, someone in this airport is in serious danger. You are the only one who can save them.
[We see Charlie and Claire cooing over Aaron and Locke points at them.]
BOONE: Not them, they'll be fine -- for a while.
[Locke sees Sayid, Sun and Jin. He points as Jin and Sun argue. Sayid pats Jin's back.]
BOONE: I think Sayid's got it.
[Locke sees Hurley working as an Oceanic counter person. Hurley types the numbers into the computer.]
BOONE: Not Hurley.
[Locke sees Desmond dressed as a pilot walking and laughing with some beautiful flight attendants.]
BOONE: Forget it. He's helping himself.
[Locke sees Kate and Sawyer, very chummy in line. He sees Jack going through a metal detector, and getting wanded by Ben. Locke starts waving his arm frantically.]
BOONE: There's nothing you can do for them. Not yet. First you have to clean up your own mess. [We can hear "clean up your own mess" being repeated in the background. Boone stares intently into Locke's face, then disappears. Locke is suddenly alone in the airport sitting at the bottom of three escalators. Boone appears at the top.]
BOONE: Come up here, John. [We see Locke dragging himself up the escalator using his arms. When he gets to the top he puts his hand in a pool of blood and then sees Eko's stick.]
BOONE: Clean it up, John.
[We see that Boone is covered in blood with his shirt torn. He looks as he did in Locke's dream from Deus Ex Machina.]
BOONE: They've got him. You don't have much time.
[Suddenly Locke is back in the sweat lodge. He starts to leave and suddenly we see the image of a snarling polar bear's face. Locke stumbles out of the sweat lodge, frightened.]
CHARLIE: John! What happened? Are you alright?
[Locke picks up his knife and pulls it out of the sheath.]
CHARLIE: What are you doing?
LOCKE: I'm going to save Mr. Eko's life.
Ok. John was obviously communing with the island during this vision quest (same as Boone in S1). However, the island has foresight into the what happens when, as Boone says, "They'll be fine...for a while," or "There's nothing you can do for them, not yet," referring to Charlie/Claire and Jack, Kate and Sawyer, respectively. The island also gave John the hints at what he needs to do next and Boone tells him to "Clean it up, John," referring to Ekos' stick. He also gave it a sense of danger and urgency, "They've got him. You don't have much time." I know, another time reference. John took this to mean that Eko was in immediate danger, which he was and John saved his life by fending off the polar bear.
So. Why did the island want John to save Ekos' life if the smoke monster was only going to kill him a few episodes later? Did the monster simply want Eko to be sorry for the life he had lived, and that he wasn't, it killed him? It just seems funny to me that Eko would be spared (by the island?) only to receive damning judgment and death (by the monster) only days later.