Make up a treasure hunt list of items to find while on an afternoon walk or hike. You could make up the list while driving to the starting point of the walk.
Items should be related to nature, God or Biblical themes. Perhaps one list for the whole group, making it a team effort, not competitive.
Some ideas for your list include: A heart shaped rock, a stick in the shape of a cross, 5 feathers, 5 different bird specie sightings, 5 different flowers, a long leaf, a reptile sighting, 3 different ant specie sightings, a reflection of a tree, Something of each color of the rainbow, Something close to perfectly round, moss, a drip of water, a butterfly, a snail shell, a nut/seed, something that relates to [insert a Bible story].