DANGS, India — Christianity is a major threat to Indian nationalism, organizers of a three-day “reconversion” rally held in February in Gujarat state indicated during the closing ceremony. Organizers of the Shabri Kumbh — Hindu “reawakening” rally — including Hindu extremist organizations such as the Rashtriya Swayamsevak Sangh (RSS or Indian Volunteer Corp), led the 60,000-strong crowd to repeat, “I…