Sundar felt that his religious pursuits and the questioning of Christian priests left him without ultimate meaning. Sundar resolved to kill himself by throwing himself upon a railroad track. He asked that whosoever is the 'True God' would appear before him, or else he would kill himself; that very night he had a vision of Jesus. Sundar announced to his father, Sher Singh, that henceforth he would get converted into the missionary work of Christ. His father officially rejected him, and his brother Rajender Singh attempted to poison him. He was poisoned not just once but a number of times. People of that area threw snakes in his house, but he was rescued from mistreatment by the help of a nearby British Christian.[5]
On his sixteenth birthday, he was publicly baptised as a Christian in the parish church in Simla,[4] in the Himalayan foothills. Prior to this he had been staying at the Christian Missionary Home at Sabathu, near Simla, serving the leprosy patients there.