The photos that Sam shows the banker while trying to get the loan are actual photos taken by the real Sam Childers in Sudan. They can also be seen during the closing credits.
The real Sam Childers, on whom the story is based, shows screenings of a heavily-edited version of the film in churches around the world, the proceeds of which are used to support his ongoing work in South Sudan.
Epilogue: "Joseph Kony and his Lord's Resistance Army continue their reign of terror in northern Uganda and southern Sudan. Amnesty International estimates that Kony and the LRA are responsible for over 400,000 murders and 40,000 child abductions. These children are tortured, raped, sold into sex slavery, and forced to take part in ritualized killing by LRA commanders. To this day, Sam Childres fights for the children of southern Sudan and northern Uganda. Sam and Lynn are still together. Lynn runs the Shekinah Fellowship Church in Central City, Pennsylvania."
Vera Farmiga was the first choice to play Lyn, but dropped out due to pregnancy. She was replaced by Michelle Monaghan.
The city Noblesville mentioned in the movie when describing roofing jobs is actually a city outside of Indianapolis and not in Pennsylvania. Jason Keller, the writer of the film, is from Indianapolis.