I understand Missional to mean every member of the body of Christ living as a local missionary to their own community. Wikipedia offers this quote:
"No one can say: ‘Since I’m not called to be a missionary, I do not have to evangelize my friends and neighbors.’ There is no difference, in spiritual terms, between a missionary witnessing in his home town and a missionary witnessing in Katmandu, Nepal. We are all called to go—even if it is only to the next room, or the next block.”"
These arguments do nothing for me and don't really even interest me, much less convict me. They are founded in philosophy, not scripture, and the philosophy doesn't move me.
God told Abraham:
Gen 12:1-3 Now the LORD had said to Abram: "Get out of your country, From your family And from your father's house, To a land that I will show you. I will make you a great nation; I will bless you And make your name great; And you shall be a blessing. I will bless those who bless you, And I will curse him who curses you; And in you all the families of the earth shall be blessed."
Gen 17:7-8 And I will establish My covenant between Me and you and your descendants after you in their generations, for an everlasting covenant, to be God to you and your descendants after you. Also I give to you and your descendants after you the land in which you are a stranger, all the land of Canaan, as an everlasting possession; and I will be their God."
No one in Abraham's family was called to be a missionary - not one soul. For all pragmatic purposes, there was just one saved family on the Earth making every other living being a mission field. God sent Abraham into that completely virgin field there in Canaan, and didn't ask Abraham to preach one word of the Truth. God DID command Abraham to "go," but never said a word about evangelizing. That's a pretty significant omission if we're all "sent."
God did, however, carefully command Abraham to sanctify himself and his household.
He didn't tell Abraham to spread the Truth at all. He told Abraham to surgically mutilate himself and every other man in his household, but God didn't say a word about preaching anything.
Gen 17:10-11 This [is] My covenant which you shall keep, between Me and you and your descendants after you: Every male child among you shall be circumcised; and you shall be circumcised in the flesh of your foreskins, and it shall be a sign of the covenant between Me and you.
Circumcision was a physical act of sanctification, of holiness, of setting one's self aside for relationship to God. Abraham was commanded to holiness, not to missions. And Abraham was promised that by keeping the covenant of holiness, all the nations of the world would be blessed.
The kingdom needs missionaries, men and women gifted by the Spirit to the work of outreach. And every healthy church will grow missionaries in due time. An old pastor once said the purpose of preaching was to humble the sinner, glorify the Savior, and promote holiness. If we do these three things, in this order, missionaries will spring up in a healthy body just like feet in a healthy infant.
If we decide we are "missional" churches, we'll be no healthier than a body with 200feet and no hands, eyes, ears, noses or sense.