Ephesians 4:4

There is one body, and one Spirit. — The words “There is” are not in the original, which starts with a striking abruption, and with that terse concentration of thought and word which marks out an embryo creed.

The “one body” is the Body of Christ, “from whom it is fitly framed, joined together, and compacted,” so that in every part “it grows up into Him.” But this communion with God in Christ being “the life eternal,” the Holy Ghost, by making it effectual alike to the Church and to the individual soul, is the “Lord and Giver of Life.” Hence, His presence is spoken of as being to the body of Christ what the spirit is to the natural body — the uniting and vivifying power for all its members. Under the same idea we have (in 1 Corinthians 12:13), as a description of the first entrance into the Church of Christ, “By one Spirit are we all baptised into one body... and have been all made to drink into one Spirit.”

Even as ye are (or rather, were) called in one hope of your calling. — The connection, though not at first obvious, is clear on consideration. Since the grace of the Holy Spirit is not only the “seal” of regeneration, but also the “earnest” (Ephesians 1:14) of future perfection, the mention of the one Spirit suggests naturally the “hope of our calling” (i.e., the perfect unity of heaven). In this, in spite of all natural and spiritual inequalities, and in spite even of our divisions and strifes upon earth, all Christians are still actually one. Hence the communion of saints is perhaps most clearly realised in the times of high spiritual aspiration, and in the near presence of death.