"I want people to feel hopeful [after watching this film]," Wahlberg told CNN in a recent interview. "And encouraged that, you know, love will always win and we'll come together and be victorious."
The film, directed by Peter Berg, follows the lives of several victims and police officers on the day of the 2013 bombing and the four-day-long manhunt that ensued.
"Every day [on set] was difficult," Wahlberg said. "Telling a two-hour story about an event that took place well over one hundred hours is a difficult thing to do."
Wahlberg, a native of Boston, told CNN that at first he was "reluctant" to take on this film.
But then, he said, "I realized, well, they're going to make it anyway and if they're going to make it then I should do it and make sure that I control it, because it's such a sensitive subject and I want to make sure that we get it right and honor everybody, especially the victims."
Wahlberg said that he spent time meeting with victims of the attack and their families, and felt afterwards that he had a personal responsibility to tell their stories.
"It was extremely difficult but I think they felt a sense of relief and comfort knowing that I was there because now they had a single person that they could hold accountable," Wahlberg said. "And I realized that and I felt even more pressure and that's why I told Pete [Berg], I don't care but we have to do it this way. Nobody is better for the job because nobody cares more than me."
The film closes with images of locals proudly displaying the slogan "Boston Strong." Wahlberg said this speaks volumes about the city he loves.
"It's brought people closer together," he said. "It's remarkable when something like this happens. There's two kinds of people: people who run away from the problem and people who run towards the problem. To see everybody rally together in the way that they did was absolutely amazing."
"Patriots Day" opens in New York, Los Angeles and Boston on December 21 and nationwide on January 13.