Summary: "Long, long ago, much over a thousand years ago, he had once asked Michael about the complex human notion of love, which he had failed to understand for a long time." Castiel loves Dean Winchester and for him, he would probably do anything. Destiel. Slash. Spoilers for S4-S5 a little.

Disclaimer: I neither own Supernatural, nor the song.
AN: So….the song is Angel with a shotgun, by the cab. Freaking beautiful song, seriously. Look it up. Totally works for Destiel. This is a fic. A just a short oneshot. Kinda like a musey one again. Happy Destiel times this time. Spoilers for S4 and S5 a little. I'm using two verses, because I love the song and wanted them both. Deal with it. Not a song fic. Just the weird thing like some of the others I've done before. Random set in S5, early on. Established Destiel.
Warnings: Aside from spoilers, I can't really see much.

/

They say before you start a war,

you better know what you're fighting for.

Well baby, you are all that I adore,

if love is what you need, a soldier I will be.

I'm an angel with a shotgun,

fighting til' the wars won,

I don't care if heaven won't take me back.

I'll throw away my faith, babe, just to keep you safe.

Don't you know you're everything I have?

..and I, wanna live, not just survive, tonight.

/

Castiel glanced down at the hunter, who was dozing lightly against his chest whilst they lay together on one of the king sized beds in the Winchesters current motel room. He had one arm curled around Dean's waist, whilst his other hand was curled into his short hair, fingers lightly moving along his lower scalp. He loved it when Dean slept. In fact, he loved it when Dean did most things, since he loved Dean. He tilted his head back and glanced at the ceiling thoughtfully.

Long, long ago, much over a thousand years ago, he had once asked Michael about the complex human notion of love, which he had failed to understand for a long time, both before and after that conversation. The archangel had replied with;
"Do not concern yourself with such things, Castiel. The notion and experience is solely reserved for humans. You do not need to understand it, as angels cannot and do not experience love for anyone other than our father." The answer had failed to satisfy his curiosity and he wasn't entirely certainly that he believed it, but he hadn't questioned Michael or the matter any further. Of course, he had understood love shared between a father and a child, and between brothers and sisters. For angels were supposed to be a family, every angel was supposed to love their father, and the majority did. As for sibling love, he understood this very well as there were a few angels who he had once been particularly close with. He had actually meant romantic love, that which had been a mystery to him. Yet Michael had claimed they were incapable of love.

Only now, looking back retrospectively was he aware of how truly wrong Michael was. Angels could love, he had come to realise that through his own personal experiences with Dean Winchester. Initially he hadn't quite understood how he'd felt, because he hadn't ever really been able to understand love, not even when he was in it. How was he to know that what he felt for Dean was love? Luckily, for the both of them, Sam was quite intelligent when it came to the matter of love, having experienced it himself. The younger brother had spoken to each of them independently, spending particular amounts of time with him and patiently explaining love, and all that he and Dean could have together, all that they could be. However, Sam certainly was surprised when he'd appeared in their motel room that very same night and all but kissed Dean into submission. They had much to thank the younger Winchester for, the fact that they were together being the principal thing. Were it not from him, Castiel probably wouldn't have understood and Dean probably would've been too nervous to act.

Love had caused Castiel to do many things recently for the man currently sleeping upon him. Initially, it had caused him to question heaven and the will and the orders, question what was right and wrong. After that, it had caused him to disobey, for Dean. To rebel, to go against the will. He was now hunted, and despite the fact that it was difficult and frightening, despite the fact that he sometimes lost his temper, he would repeat his actions again in an instant. For this man he would die. He had died, even. For him and his brother, he would do anything, no matter the cost to himself. He was in deep now, wrapped up in a current too beautiful to fight. So instead, he would swim with it and allow it to wash him further away from the shore. He would fight for him and if he had to die again to save him and his brother, and the world…Then so be it.

Yes, Michael had certainly been wrong all that time ago. Just because he had never experienced love himself, like many angels, it didn't mean that they were unable to feel it. Castiel was a testament to the fact that they could. He knew love and he knew that it was something worth losing everything else for.