User blog comment:Bharatram1/Who is stronger ? Lilith or Azazel ?/@comment-86.140.130.217-20120512221938/@comment-4920092-20120513192435

It's likely a backup plan - in case nobody in Sam's generation was strong enough/willing to kill Lilith. And he wasn't really worried about Lucifer's vessel dying - I find it likely that an angel doesn't need permission to possess a dead person. But if I'm wrong, Lucifer could have easily resurrected Sam.