PCRT Season

Phil has taken off (or maybe he is taking off; I can't keep up with him) to Atlanta for the PCRT being held there this weekend. (He will be back to preach on Sunday.) The theme this year is "Precious Blood: Christ's Atoning Work." Here are the plenary addresses:
Necessary Blood
Redeeming Blood
Cleansing Blood
Offensive Blood
Precious Blood

Hhmm...there is a common thread here. I can't quite figure it out.