After my first viewing of The Matrix, I was wondering why the Oracle lied and told Neo he wasn't The One. I eventually hypothesized that she needed to lie to him so that the proper sequence of events could be set into motion. It was only upon a later viewing that I realized that her actual words, "Your next life, maybe. Who knows." were completely correct, since Neo had to die first before becoming The One. —Onigame
The Oracle: Now here's the part where I go hmmm, aaahhh, interesting. And here's the part where you say...
The Oracle: But you already know what I'm going to say.
Neo: ... I'm not the One.
The Oracle: Sorry, kid. You got the gift. No doubt about it. But it looks like you're waiting for something.
Neo: For what?
Your next life, maybe. Who knows.
- For Trinity to love him. To give him purpose. And Neo doesn't fully become the One until after he's died. So he was waiting for his next life. - Saintheart
- It also explores the theme of belief. Morpheus believes Neo is the one. Neo doesn't believe he's the one. Trinity comes to believe Neo is the one. It doesn't matter what Morpheus or Trinity believed, it matters what Neo believed. Trinity confessing her love and the Oracle's prediction finally allowed Neo to believe as he came back to life. Remember the Jump program? "Free your mind" indeed.
- The Oracle told Neo that he isn't The One, so that he would not set his own life over Morpheus', in a situation later in the movie, where Morpheus is in danger. She needs Morpheus to live on, and knows Neo will only save him if he knows he is not the One. "Fuck it, might as well risk my life for this guy, The Oracle said I wasn't The One anyway". — Merzer