I don't exactly recall all the details from the previous season, as the show was mostly miss than hit for me last year, but I tuned in this season and about half the cast from last year is completely gone, including the associate pastor Jeremey London and his adoptive son and the people that Lucy's husband worked with, and most of the extras that lived in the house (including the absence of Ashlee Simpson )

Did they ever resolve those characters' story lines or were the throw away lines about them added into the series premier all that we get? I hate shows that leave us wondering about characters at the end of one season, then the actors don't sign back on for the next season, and it's all this awkwardness at the beginning of the next season as they try to fix things.

Reverend Camden condemmed them all to hell.

I don't know exactly what happened to him, but I bet Jeremy London's being caught with a bag of weed probably didn't help his cause to return to the family friendly show.

TK

There was no explanation as to why Jeremy London's character left, just that he did.
There's been no mention of where Roxanne went to.
Cecilia (Ashlee Simpson) left for college.
Ruthie's boyfriend and his mother left to live closer to his dad (whom supposedly got some great job far away).

Biggest developement is that Ruthie is starting to get boobies.

Are you asking for something on this show to make sense?

Roxanne joined the army and got shipped to Iraq. That was in the season finale last year.

Roxanne = Lynddie England, or haven't you heard?