Someone get Cas a glass of water. OTL
[At Alma's questions, Cas takes a moment to pause. Really contemplate this over. He had been human, he had died for the sake of war, and what had it all led to? What had it meant for everyone?] Awful, Alma. Truly, I'd feel... much like how you're feeling at this moment.
What Dean meant, [glances at the man for a split second] is exactly what he said. There really isn't anything you can do about your situation--whatever it is. However. You can choose to accept this fate and immerse yourself in self-pity and active hostility or. You can fight against it. Think about this thoroughly now, take a moment to still your wrath. Where are you? What have you been doing since you've arrived here? Alma, believe it or not, you do know who you are. You have been shaping and molding yourself into the person you want to be. You have a choice in the matter.
Dean, Sam, and I... we chose to fight. The Winchesters abandoned their destiny and I abandoned heaven once because what we knew, we knew to be right. Isn't that what it all comes down to? What choices we make will have the best possible outcome?
... Isn't that what Allen and your other friends were trying to do? In order to protect you, yes, they lied. But for your sake. They intended to keep you safe. To keep you from harming yourself as you're doing now.
[Deep breath. He's getting worn down.] What you learned last night, consider it an advantage. Use that knowledge to further your progress into life. Overcome this hardship and become a better human being. [Looks straight into Alma's eyes like Alma had done previously to Cas. But it isn't a hard gaze--it's completely calm.] Don't let this consume and destroy you.