The first duty of Missionaries is to spread the Gospel or Good News in order to bring people to salvation
Matthew 28 18 And Jesus came and spake unto them, saying, "All power is given unto me in heaven and in earth.
19 Go ye therefore, and
teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy [Spirit]:
20 Teaching them to observe all things whatsoever I have commanded you
the exclusive possession or control of the supply of or trade in a commodity or service.
