They started by hanging 18 hanging lightbulbs from string behind the screens. They ran power to them from a dimmer pack so they could dim them at the lighting board. Those cost about $300 from partylights.com.
Caleb wanted to frame the stage with some simple lights and found some pre-lit LED trees at Walmart ($30 each). The light bulbs around the trees were also from partylights.com and they had those from a previous set design.
The trees were the easiest part. A landscaper happened to have exactly what they needed and dropped them off at the church. They dried them in the basement for 3 weeks and then spray painted them a flat white. They had some 1″x4″ already and some stands that just screwed the 1″x4″ to to make a sort of support fence for the trees. Then Caleb cut them to around 7′ tall and spaced them about 1′ apart on the fence, fastening them with suspension strap (hardware store for $10).
They lit them with 4 Elation TriPar LED lights on the ground shooting across the backdrop.