God created humans in His image to have dominion over His creation. He gave them free will to choose to obey or disobey. Adam and Eve chose to disobey and sin, which corrupted human nature. God became the first missionary by calling to Adam and Eve after they sinned and explaining His plan to save humanity through the sacrifice of His Son. Now God calls all Christians to be missionaries and spread the gospel to others as the "salt of the earth" and "light of the world" in order to save the world from corruption and destruction.