Sam placed the archangel blade to a dead Lucifer's neck and made a slit in it.
In the cut past the little blood he still had after his cold heart stoped beating, there was a glowing blue-ish liquid or vapor. Sam didn't really know what grace exactly was.
'Sam what are you doing? He's dead.' Jack thought. He didn't see what Sam was really doing.
Sam, still kneeling, said "I was right." he turned to jack and lifted him into his arms he turned him to Lucifer and the grace flowed to a dead Lucifer to a weak jack and quickly settled in into its rightful place.
'Please work.' Sam thought with a hopeful look on his face.
Jack was still in Sams arms when his eyelids opened revealing his beautiful yellow-golden eyes.
Jack sat up abruptly like a child waking up after having a nightmare. He was breathing heavily like he had been scared.
Sam helped Jack stand up straight and calm down. His eyes finally went back to blue as he looked at Sam a bit confused as to why he saved him.
"Why?" Jack said to sam.
"We need everyone we can get to save dean. And plus, you are family and just because you made a few mistakes doesn't mean that you are a bad person." Sam told Jack to reassure him that someone still cares about him.
"Thank you, Sam."
"No problem. Now let's go back to the bunker and see what we can do." Sam was confident that they would save his brother.
"Sam?" Jack question
"Yeah."
"When we find Michael, we are going to 'kick his ass', right? Jack use of air quotes added to how innocent he said it.
Sam laughed a little "Sure."
"Why when you stood up from Lucifer, why did you say you where right?" Jack asked.
"Well, I figured since Lucifer only had your grace for a short amount of time, it didn't have time to settle in and die with him." Sam explained "And I was right."
"And if it didn't work?" Jack asked.
"I don't know. But let's get back to the bunker." Sam said.