From the article:
Lewis said Nolen was fired right before the attack, and that he then drove from the building that houses the company's human resources department to its main distribution center.
This is no different than a disgruntled worker who goes on a rampage. I wouldn't personally consider it a religiously motivated attack. He just borrowed their language.
The records show that Nolen has what appear to be religious tattoos, including one referencing Jesus and one in Arabic that means 'peace be with you.'
Off-topic here. Are Muslims allowed tattoos?