Rakul Preet Singh, Sidharth Malhotra and Ajay Devgn will star in Indra Kumar-directed comedy film 'Thank God', as per a report. The film is about the hilarious adventures of a couple of good-natured, goofy men who are out to reform society, another report stated. Reportedly, 'Thank God' is Indra's passion project and he has been scripting the idea for years.