 Drugs used in chemotherapy, such as capecitabine and gemcitabine, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Monoclonal antibodies, such as bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry tumor-killing substances to them. Bevacizumab may also stop the growth of pancreatic cancer by blocking blood flow to the tumor. Radiation therapy uses high-energy x-rays to kill tumor cells. Capecitabine may make tumor cells more sensitive to radiation therapy. Bevacizumab may make tumor cells more sensitive to both chemotherapy and radiation therapy. Giving chemotherapy and bevacizumab before and after radiation therapy may kill more tumor cells. This phase II trial is studying how well giving capecitabine and bevacizumab together with radiation therapy followed by gemcitabine and bevacizumab works in treating patients with locally advanced pancreatic cancer that cannot be removed by surgery. 