Here's my latest theory. I've always liked the idea that the John vision was Gabriel acting at God's behest, because to me Gabriel is the only one who could legitimately say that he could never fool Sam. It also makes sense that God would resurrect Gabriel to help out at this point. After all, Gabriel was the only archangel who truly places humans above the angels, having decided to side with them during the apocalypse. (I'm kind of ignoring the fact that he also had tormented/killed some humans along the way ). But the next cage visions maybe were from Lucy, because why would God or Gabriel think that horrible visions such as those would help convince Sam to return to the cage? Presumably, they would have the opposite effect. Unless they were intended to somehow reduce the awful power and effect of those memories through exposure? Not sure. It could also be that they were sent from Lucy to torment Sam just because he now can due to the fissures in the cage. But the last cage vision in which Sam was calm and Lucy seemed almost kind were from Gabriel, the final push to induce Sam to revisit the cage. And to me, the best evidence that that vision was from Gabriel was the burning bush. that was kind of a funny flourish to the vision, perfectly in keeping with Gabriel's sense of humor. Which brings us to next week. Maybe Lucy does try to mess with Sam's mind and the wacky Christmas visions are Gabriel's efforts to counter what Lucy is trying to do. The craziness of the vision is exactly along the lines of the Changing Channels alternate realities brought to the boys courtesy of Gabriel. So that is my current theory, at least for this moment in time.

I think that Lucifer was lying trying to break Sam's will, and all Sam's vision arу from a different source. I think they are from God, but may be not directly, but it may be from one of his emissaries. I would like them to be from Abel, just because I would like to hear his point of view as I think that Cain's decision to kill his brother can't be right whatever circumstances it was made under. I personally think that Cain made a mistake believing Lucifer and not believing his brother, and Abel was really speaking with God or rejected the Devil, but Cain just didn't believe in his brother, acting out of fear that his brother is weak and can't resist Lucifer.
-Disgruntled.

I agree... Sam's visions/dreams come from at two sources, one certainly Lucifer, the youngJohn dream in 11.04 almost certainly not. I'm going with two possibilities 1) Gabriel, assuming he's alive as the actor/Director and producers say he is - Gabriel is the only one who 'could never fool the brothers' and there have been lots of 'candy/candy wrapper' references in almost every episode except the premiere and the msf. Plus the garish wallpaper where the boys interrogated demon Marco in 11.06 was right out of S5's 'Changing Channels' where the boys outed The Trickster as an angel. 2) "God' with 'Chuck's sense of humor. 'God' would know more about one of Mary's favorite songs and both Gabriel and 'God' would praise Dean for how well he took care of Sam and 'Baby'.

I agree that the visions of the cage etc, were probably from Lucifer. I tend to think the arrival of The Darkness caused some kind of disturbance that enabled Lucifer physic access that he hasn't had since he was put back in the cage. The visions of young John seemed very different in tone so I believe it was sent by someone who had a more helpful agenda. God? Gabriel? Kevin (is he still in the veil)? I tend to lean God because anyone else would less round about in the delivery of their message. Also he has a more familial stake in this one. I have no clue. I am interested to hear what others may think too.