Therefore, the what we do and how we do it and the being sent somewhere and being received by someone and all the relationships behind it is very important to the success of mission. To accomplish these tasks a leader is going to need to prepare his or her congregation by training them. A missional theology is not content with mission being a church-based work. Rather, it applies to the whole life of every believer. Every disciple is to be an agent of the kingdom of God, and every disciple is to carry the mission of God into every sphere of life. We are all missionaries sent into a non-Christian culture. The word "mission" means sent. Many organizations have a "mission" statement. They include hotels, the military, restaurant and health care company. If we trace the words historic roots, we find the word comes from the Latin "mittere" used to translate the Greek "apostelein". It gives us the word “apostle”. This is the "sent" ones or one who is "sent". The word Catholic “mass” comes from this word. Isaiah 19:20 states a Savior will be "sent". John 3:16-17 "God sent" his only begotten son. John 20:21 states Peace be with you. As the Father has "sent" me, so I send you.
(http://www.globalministries.org/resources_mission_study_college_of_mission_the_origin_of_theology_in_god (Taken