From George W. Peters’ excellent book A Biblical Theology of Missions:
“The Great Commission is not an isolated command arbitrarily imposed upon Christianity. It is a logical summation and natural outflow of the character of God as He is revealed in the Scriptures, of the missionary purpose and thrust of God as unfolded in the Old Testament and historically incarnated in the calling of Israel, of the life, theology and saving work of Christ as disclosed in the gospels, of the nature and work of the Holy Spirit as predicted by our Lord and manifested on and after Pentecost, and of the nature and design of the church of Jesus Christ as made known in the Acts of the apostle and the epistles. It forms an organic unit and an integral part within that revelation and receives its true meaning and force only if seen in this larger relationship.
“The Great Commission does not make Christianity a missionary religion. The latter is such of its source, nature and total design. The apostles became missionaries not because of a commission but because Christianity is what it is and because of the indwelling Holy Spirit who is an outgoing and witnessing Spirit. Christ Himself speaks of the mission of the Holy Spirit as a witnessing mission (Jn 15:26; 16:8-15). Thus, if the particular words of the Great Commission had never been recorded or preserved, the missionary thrust and responsibility of the church would not be in the least affected. It prospers wherever Christianity is truly known, thoroughly believed, genuinely experienced, and implicitly obeyed.” (173)
HT: Dave Hosaflook