Snape Loved Lily???

"Snape is definitely a good guy." Ya heard this... so what? It's quite obvious, isn't it? With six books continuously trying to make you mistake Snape for all the bad things happening to Harry and finally turning him into a near-hero status, it's not that easy to accept him as the bad guy with just one act - of killing Dumbledore. Dumbledore never feared death and was literally begging Malfoy to kill him till the Death-Eaters arrived and it doesn't make a bit of sense for him to ask Snape to leave him alone by saying "Please severus...". For all we know, it might have been Dumbledore's plan from first to get himself killed at the right moment, of course for something bigger and Snape could have hesitated at the end, so that Dumbledore was forcing him to kill him as quickly as possible. You can read all this here and thousands of other fan sites.

But what none of them could explain was the million dollar question "What made Dumbledore believe Snape, at first?" Here lies Rowling's skill at not letting the readers know too much too soon. With the little information we have on Snape history, there no way of answering that, with as much conviction as saying R.A.B is Regulus Black. From this point forth, we shall be leaving the firm foundation of fact and journeying together through the murky marshes of memory into thickets of wildest guesswork.

Snape Loved Lily

We know nothing of the feelings of Snape towards Lily Potter apart from that one memory where she tries to protect him from James. Of course, he insults her and calls her a mudblood. But what else do you expect when he is angry and vulnerable? Also, it is possible that that one act could have made him feel ashamed of himself later when he went to his room and could have planted the seeds of his feelings for her. Of course, these feelings were not reciprocated, as Lily later went on to love James. I'm saying Snape never had the courage to express his love for her. This is purely my guess, but it seems very logical as it answers many questions like:

1. Why Snape hated James to such an extent?
2. Why Snape hated Harry? (He resembled James and couldn't stand the fact that he was the product of Lily and James' love)
3. Why he felt sorry when he heard that it was actually Harry Potter that Voldemort tried to kill when he heard of the prophecy? ( Now this is the strongest clue for my theory. Snape didn't know whom the prophecy referred to initially. He went and told his master about it. When Voldy went to the Potters' residence he killed Lily before trying to kill Harry. This made Snape sorry for what he did. It hurt him badly. He never expected this to happen. Again it re-affirms the fact that Dumbledore keeps harping on: "Love is the greatest thing in this world". It made Snape think if what he was doing was right or wrong. He came and pleaded to Dumbledore telling him his innermost feelings for Lily. No amount of Occlumency would have hidden such deep, heart-felt regret. And Dumbledore is not one to be easily deceived of such things. He believed Snape and made him turn against Voldemort.)
4. What's so significant about Harry's green eyes that Rowling keeps telling she'll explain in every book? ( Snape in the final battle between Voldy and Harry, will be reminded of Lily when he sees Harry's eyes and help him or die protecting him or something like that.)
5. What are the two important things about Lily, that Rowling said will be revealed in the next book? (Well, this surely appears to be one of them)

These are some of the questions that will definitely be answered to an acceptable degree if my theory is true. Again, this is just my "theory". But definitely "my" theory. Hope it turns out to be true.

P.S. Let me put this in writing. I have a bet with my friend Rahul. He says Snape is bad and I say Snape is good. The bet is for a thousand rupees. This is just so that I don't forget to collect my money later.