If you desire to work and stay in the United States temporarily in your religious capacities then you have to obtain temporary religious worker (R-1) visa. The duration of R-1 visa is determined by the Department of Homeland Security, U.S. Customs and Border Protection (CBP) officials. The CBP officials are authorized to determine the duration of R-1 visa that means your stay in the United States.
If you want to stay or work in the United States for more time than your authorized stay, you should apply with United States Citizenship and Immigration Services (USCIS) well in advance. However, extension of the duration of R-1 visa is possible if,
Please note that failure in departing from the United States on time can make you out-of-status. It may void your visa and you may not be eligible to apply for visas in future. For a problem-free stay in the U.S. with a nonimmigrant visa check out all the rules and regulations on the USCIS and CBP Websites.