Say, "O Mankind! If you have any doubt about the System that I am trying to establish, and if you believe that other parallel systems can be of avail to you, let us go ahead with our programs. I worship not and obey not those whom you worship and obey instead of Allah. But I obey Allah Who causes you do die (and Who controls the Laws of life and death of individuals and nations). I have been commanded to be of the believers."