Uchiha Obito was never a liar! He hates them; how could he be one himself?
Obito to Kisame: "This world holds nothing but lies"
Obito is a man who has a deep sense of loathing for liars and the act of lying itself! There is proof of this:
The reason he wants to put the world that exists, to sleep, change its fate with an incredible; universal Genjutsu, is that he doesn't believe the truths of this world anymore.
Although I am certain that Kakashi tried his very best, the one promise that Kakashi made to Obito, in exchange for his own life; and the greatest weapon in his arsenal, the Sharingan, was that he would protect Rin, the person Obito cared about the most. Circumstances might not have been on Kakashis side, and due to very bad luck, Kakashi could not keep that promise to a friend that sacrificed everything for him.
To Uchiha Obito, who survived, this was betrayal of the highest order...........a lie; a lie that demolished his faith in the existing shinobi world.
You simply do not break your promises to an Uchiha, especially one who sacrificed his own life for yours.
So how can someone like Obito; who absolutely despises liars and lies alike, take up the role of one himself?
The answer lies.......in the power of the name! It was his job; a job given to him by the man who originally owned that name. Uchiha Madara gave him that title, until such time as he would be revived, Uchiha Obito would fulfill that roll.
He did it perfectly! Almost too convincingly; when I looked upon Obito after his mask had come off, I could not believe it nor accept it for a time. Even as Edo Madara had already left his coffin, I still kept believing that the man behind the mask was still some form of Uchiha Madara. That is how good he was at his job!
So fellow NBers......do not think of his grand charade as a lie! He was simply fulfilling his duty. A duty left to him by the man who showed him the true power of the Uchiha clan and the things that could be accomplished with that power.
After the first few posts, I realised most people won't even get this thread, they see things only as one or the other, right or wrong, good or evil...truth or lies. For you to understand me....you must look beyond those things.