A fabric factory worker said he had told the event organisers he had no intention of changing religion.
"We told them we don't to become Christians. We have been given these badges with different colours for those who have agreed to convert to Christianity and those who have not,” he said.
“There are a lot of Indians and Burmese people who have agreed to join the religion – but we are not going to give in to that."
The worker said some of the pastors were from Burma and they also used to be Buddhist before they settled in Mizoram.
Burmese pastor U Khin Maung Myint said that the gathering had only been intended as a way of letting people know more about Christianity and that there were actually a number of Buddhist and Muslims who had chosen to convert to Christianity.
"Some people came here [to the gathering] out of politeness to their employers. We are only here to tell them about God," the pastor said.
"We could not let them leave the gathering because we had planned to hold it for four days – we were only asking them to stay with us whether they were interested or not,” he said.
“I used to be a Buddhist myself and I am now spreading the message of God [to the rest] only to save them."
Mizoram state has a large Christian population, and the majority of the around 60,000 illegal migrants from Burma are from the bordering Chin state and speak the same language and follow the same religion as the majority of the Mizoram people.
There are also about 2000 Burmese workers from Sagaing division's Amarapura, Shwe Bo, Monywa and Kalay townships, working at fabric factories in Mizoram.