And ye shall know that I am in the midst of Israel, and that I am the LORD your God, and none else: and my people shall never be ashamed.
And ye shall know that I am in the midst of Israel - as in the Old Testament dispensation God was present by the Shekinah, so in the New Testament first, for a brief time, by "the Word made flesh dwelling among us" (John 1:14), and to the close of this dispensation by the Holy Spirit in the Church (Matthew 28:20, "Lo, I am with you alway, even unto the end of the world"), and probably in a more sensible manner with Israel when restored (Ezekiel 37:26-28).
And my people shall never be ashamed - not an unmeaning repetition from Joel 2:28; the twice-asserted truth enforces its unfailing certainty. As the "shame" in Joel 2:26 refers to temporal blessings, so in this verse it refers to the spiritual blessings flowing from the presence of God with His people (cf. Jeremiah 3:16-17). So in the finally renewed and regenerated earth, "Behold, the tabernacle of God is with men, and He will dwell with them, and they shall be His people, and God Himself shall be with them, and be their Gad" (Revelation 21:3).