Humans often believed that they were the children of God, while angels were merely His soldiers of faith.
What an idiotic thing to say.
They don't know what He sees in them, but they know that His word is law. The one who dared to argue for their right had set the example that they had no say in the matter.
They were the ones who He created first. They were the ones who were His children, not those flawed creations that can suffer eternal damnation.
Thus they were the only ones who could have divine gifts. Humans use heavenly and angelic to describe them when only the angels from Heaven should be able to wield them.
And the humans gifted with an ability that only they should control should be punished for such a thing. Nothing too extreme - something plausible that it could have been by its own faults that bestowed on them such a faith.
Besides, it wasn't as if their Father was scolding them or anything.
Castiel was ordered to never leave his post unless it was of grave importance. Grave importance including but not limited to: the welfare of his brothers and sisters or a summoning back to Heaven for new orders.
So when he heard a voice, a voice so soft and crisp and clear it was as if one of his sisters were coaxing for the stars to shine brighter, asking the wind to whisper instead of yell, making the snowflakes dance and twirl before they make their descent to the earth, he assumed that checking one of his sisters would be included in 'welfare'. After all, what would a Virtue be doing on Earth?
He found it odd when his travels brought him to a home in Lawrence, Kansas. He could sense another, one of his other siblings nearby. Probably here to help the Virtue and beat him here.
Still, Castiel figures that he may as well see this Virtue before she goes back to her rightful place amongst their ranks - Virtues are rare with the increase in corruption of mankind, and Castiel himself has not seen a newborn angel in a millennia.
Knowing it's against the rules, he decides to stay a tad bit longer and conceals himself from his brother tending to their sibling, murmuring peacefully as if asleep.
He is concerned and confused when the voice is suddenly cut, replaced with total silence save for the husband snoring softly next to his wife in a far room to the left.
He makes his way to the source of the noise to watch one of his brothers, Zachariah if he recalls correctly and he knows he is, with his hand over a young child's face, glowing with power.
He can hear Zachariah say, "You do not deserve such a gift." before releasing his hand. The child shulmps to the floor and he quickly disappears - most likely to return to Heaven.
Castiel is dumbstruck as to what he just witnessed. He cannot bring himself to move until sometime later, the voice that brought him here continues to sing - but instead of filling his heart with warm and joy, it is instead of sadness and despair.
Castiel thinks he understands now. This was no sister of his. This was a child, a human child, who was born with an angelic voice.
Many angels in Heaven hold grudges over humans, most in secret after what happened to their brother. He had heard rumors of angels bringing punishment to these humans, but hadn't known for it to actually be true.
Castiel himself is not one of those angels. He himself is impressed with the human race and respects his Father's wishes to devote themselves to them. He, as well as a few others, believes that there is a reason for these humans to be given heavenly traits - a reason not known to them but known only to their Father.
So he does what he knows he should do since he is here - help the child that He specifically gifted. Castiel helps the child as he much as he could, not having a vessel. He himself hums a hymn of comfort and peace, and while it may not have the same effect if a Virtue were to be singing, it seems to comfort the boy.
He places the boy back on his bed and tries to assess the damage. He couldn't have been more than two, perhaps just recent, and in his emerald green eyes were a vacant look that would never be as beautiful as they originally were.
Zachariah had punished this boy with blindness.
Castiel decides to stay with the boy, comfort him until his parents find him in the morning. By then he would be back at his post with no one the wiser.
Although he knows that this child is human, he can't help but treat him as if he was his own flesh and blood, and quietly requests of his Father to punish Zachariah for doing such a thing to a child.
"What's your name, child?" Castiel can't help but wonder allowed, knowing fully well the boy slowly falling asleep in his warm, gentle light wouldn't be able to hear him. "My name is Castiel." He chuckles. "Your personal angel for the night."
He is moderately surprised when he hears the sleepy, shy reply, "Dean… Dean Winchester."
(~Six years later~)
By now Castiel has learned how to appear to humans, and knows what his vessel is to look like if he were to ever need his help. Castiel finds it amusing that angels, powerful enough as they are, still needs the help of humans in order to interact with their Father's greatest creation. Some would argue that they, the angels, were their Father's greatest creation, but Castiel is not among that number.
Castiel has found it quite liberating to interact with the world around him and, taking the form of the man he knows is his vessel, walks around among the humans.
"In the rain the pavement shines like silver… All the lights are misty in the river…""
It's faint, but Castiel would have been able to recognize that voice anywhere. He quickly turns, searching for the source, and begins to run towards it as soon as he does.
He is in Manhattan, New York. It's a long way from where he'd previous heard this voice. Although it sounds as beautiful as when he first heard it, the emotions are not as pure and happy as they first were. These are emotions of determination, desperation, and the fading of hope. In his mind is the mantra: 'Gotta feed Sammy. Gotta help Dad with the bills.'
"In the darkness, the trees are full of starlight… And all I see is him and me forever and forever…"
And then he sees him. Young eight year old Dean Winchester, singing his heart out and holding out his hat. Castiel could spot a few green bills and he recalls the people he's seen on the street performing for money.
His eyes are still as glassy when he'd first seen them.
Castiel is breathless. Dean clears his throat, counts the money he had earned, stuffs it in his pocket before placing back his hat. He looks up at the sky before walking away.
Castiel had shed his human appearance, not wanting to risk being seen by Dean. He doesn't know why, but he doesn't want to be seen. He wants to follow Dean though, make sure he's okay.
He could hear Dean humming to himself, and very softly is still continuing to sing as he paces briskly.
Castiel could pick up how different Dean's emotions were. Before was desolate with a hint of hope, but now was hope with a smidge of sorrow. "On my own… pretending he's beside me. All alone… I walk with him till morning. Without him, I feel his arms around me. And when I lose my way I close my eyes. And he has found me."
Dean suddenly turns and is staring straight as Castiel. Staring at him with those blank eyes before abruptly turning into a motel.
Blinking, Castiel wonders if maybe the angelic humans weren't punished after all.