"And this Gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come." (Matthew 24:14 [KJV])
As ministers of the Gospel, it's your commission to preach the Gospel to the world. Jesus came with a message to the whole world, and after preaching it to a certain point He went to heaven and commissioned us to carry on from where He left off.
You're the light of the world, but you'll never know how brightly your light could shine until you go to those living in darkness. So get committed to preaching the Gospel today!