A slideshow of the photo essay accompanying this story is posted online.

A blood-red moon rises slowly into the black sky above the Amazon jungle. The low rumble of a riverboat's engine and the clatter of birds in the distant trees break the silence.

The Southern Cross hangs above us as we make our way up the Rio Negro, the largest tributary of the Amazon, the world's largest river system. This water highway provides a missions team of 25 American and Brazilian Christians an avenue to reach the small communities clustered along the shore. I am here to witness and record the journey.

About half of those aboard are medical professionals and boat crew. Among the others are a youth leader, the president of an airline company, and a contractor with his son. Some have been on this river before. Most have not. They are getting to know each other for the first time. But just 24 hours into the trip, there is a warmth and camaraderie despite the tight quarters. Their goal is to bring villagers a message of God's hope, along with urgent medical care. As they cruise through wide, dark waters and the vast rain forest, their sense of purpose as a team grows stronger.

There are an estimated 33,000 villages in the Amazon basin. Shallow-draft riverboats provide one of the few ways to reach these villages, most of which have fewer than 100 people. Jesuits built the pioneering missions in the region in the 1600s. Protestant medical missions began here in the 1930s and the efforts have been steadily growing.

Village families live in utter simplicity with few possessions. Their homes are bare wooden structures on stilts sitting high on the riverbanks for protection. Yearly floods raise the river level by as much as 30 feet.

The people wake before ...