Jessica Chastain is almost unrecognizable as Tammy Faye Bakker in the first trailer for the upcoming biopic The Eyes of Tammy Faye.

In the film, the Oscar nominee, 44, plays the televangelist who died at age 65 in 2007 after colon cancer spread to her lungs.

Chastain previously revealed to PEOPLE that she did almost 10 years of research for the role, including reading up about and watching interviews of Tammy.

The Eyes of Tammy Faye opens in theaters on Sept. 17.