In future episodes, Dexter (Michael C Hall) will contemplate issues of faith and spirituality as he continues to raise young son Harrison.
"It's a religious theme [this season], so anytime you have religion mixed in with serial killers, that's going to be controversy right there," Lee told Screen Team Media.
The actor also insisted that he still enjoys providing the humor in Dexter as geeky forensics expert Vince Masuka.
"I play a fun character and the show sometimes needs a little bit of fun to mix... in with the dramatic stuff," he suggested.
Lee previously revealed that Masuka will recruit a team of lab technicians in future episodes to assist him with his latest case.
"I have a few 'lab helpers' coming in this year," he said. "They're either going to help me or they're going to get me in trouble. We'll see what happens."
Dexter will return to Showtime on October 2.
> Dexter Colin Hanks: 'New season will shock fans'
Watch a trailer for the new season of Dexter below: