As to the commission in Matthew 28:18, etc., I think some considerations may help you as they have helped me. It was not from heaven, but from Galilee, and does not immediately connect with heaven. It was to bring the Gentiles into connection with the remnant of the Jews on earth already recognized, not to form the elect of both into one body united to Christ in glory, as through Paul’s commission. The revelation of the Trinity is not essentially and distinctively Christianity: a triune God was involved in many an Old Testament scripture, even from Genesis 1, where the plural name of God is found already with a singular verb (as nowhere when the gods of the nations are in question). But the full revelation came out on the occasion of the Son of God being manifested to Israel (Matt. 3, John 1:31) — that is, in His place on earth, the Father seen in Him, the Spirit not given by measure to Him, all the Fullness pleased to dwell in Him.
Christianity starts with a risen and ascended Christ at God’s right hand, and the mission of the Holy Ghost from the Father and the Son. Matthew 28 was from resurrection, not ascension. Paul was not sent to baptise: he accepted what he found going on, and there was no other revealed formula of baptism. God does not go back on the full revelation of Himself as Father, Son, and Holy Ghost as to the name in which the remnant will take up the testimony to bring in the nations, when the assembly is gone, though it does not appear to me to involve for them the full intelligent relationships implied in the revelation as it affects us, which depends on testimony to make good to us such relationships.
The testimony for the remnant is the testimony of Jesus, the spirit of prophecy, and will not, as it would seem, bring them beyond the names by which God was known in the Old Testament, as we find reproduced in the Revelation, with Jesus the rejected, suffering, and exalted Lamb super-added. They will not have gone over all the cities of Israel till the Son of Man be come — broken off when they were scattered from their cities, the mission will be resumed when they are again in them — doubtless others will go out to the nations: though the formal bringing the nations into their own accepted place by baptism, as in Matthew 28, only belongs, I suppose, to the future of the testimony. It did not go far beyond the manifestation of such a remnant till Jerusalem was destroyed — the work among the Gentiles being committed to Paul, who did not take Matthew 28 for his testimony. I quite think with you that the grace side of the testimony comes in with the Father, Son, and Spirit and that judgment is more connected with the Revelation side of it — “the hour of His judgment is come” (14:7)
J.A.Trench
S.T. 1915