And I say to you that you are [a]Peter, and on this [b]rock I will build My church; and the [c]gates of Hades (death) will not overpower it [by preventing the resurrection of the Christ]. – Matthew 16:18
Down through history many great traditions, Orthodox, Catholic, Lutheran, Anglican and Presbyterian have, to some great extent in their actions (even if at variance with their theology), understood this verse to be primarily a call for the extension of the Church as an institution and not the extension of the Kingdom of God and His will on earth (and much less the idea of a militant Church as God’s instrument in a war).
In light of two coinages, Church Mission and Kingdom Mission, The Great Commission clearly includes both (not just “foreign missions,” or Kingdom Mission) for that certainly what is meant by —
— teaching them to observe everything that I have commanded you; and lo, I am with you always [remaining with you perpetually—regardless of circumstance, and on every occasion], even to the end of the age.” – Matthew 28:20
Granted that it is more common to distinguish between home and foreign missions, or between monocultural evangelism and the highest priority — pioneer, cross-cultural evangelism or mission.
Our obligation is to seek the expansion of the knowledge of the glory of God and HIs Kingdom, and this would logically require us each to prayerfully seek God about doing the hardest thing we are able to do in the most crucial task we can find.
The one who practices sin [separating himself from God, and offending Him by acts of disobedience, indifference, or rebellion] is of the devil [and takes his inner character and moral values from him, not God]; for the devil has sinned and violated God’s law from the beginning. The Son of God appeared for this purpose, to destroy the works of the devil. – 1 John 3:8
To follow Jesus is to go to war.