There is one body
The church; in what sense that is a body, and compared to one, (See Gill on Ephesians 1:23). It is called "one" with relation to Jews and Gentiles, who are of the same body, and are reconciled in one body by Christ, and are baptized into it by the Spirit; and with respect to saints above and saints below, who make up one general assembly; and with regard to separate societies; for though there are several particular congregations, yet there is but one church of the firstborn, whose names are written in heaven; and saints of different ages, places, states, and conditions, are all one in Christ Jesus, who is the one, and only head of this body: and this is an argument to excite the saints to unity of Spirit; since they are, as one natural body is, members one of another, and therefore should not bite and devour one another; they are one political body, one kingdom, over which Christ is sole King and lawgiver, and a kingdom divided against itself cannot stand; they are one economical body, one family, they are all brethren, and should not fall out by the way.
And one Spirit;
the Holy Spirit of God, who animates, quickens, and actuates the body: there is but one Spirit, who convinces of sin, enlightens, regenerates, and makes alive; who incorporates into the body, the church; who comforts the saints; helps them in their access to God through Christ; makes known the things of Christ to them, is a spirit of adoption, and the seal and earnest of the heavenly glory; and the consideration of this should engage to unity, because a contrary conduct must be grieving to the Spirit of God, unsuitable to his genuine fruits, and very unlike the true spirit of a Christian: and by one spirit may be meant the spirit of themselves, who, as the first Christians were, should be of one heart, and of one soul, of the same mind, and having the same affections for one another; which sense is favoured by the Syriac and Arabic versions; the former rendering the words, "that ye may be one body and one spirit", making this to be the issue and effect of their endeavours after union and peace; and the latter reads them as an exhortation, "be ye one body and one spirit"; that is, be ye cordially and heartily united in your affections to one another:
even as ye are called in one hope of your calling;
that is, the glory hoped for, and which is laid up in heaven, and will be enjoyed there, to which the saints are called in the effectual calling, is one and the same: there are no degrees in it; it will be equally possessed by them all; for they are all loved with the same love, chosen in the same head, and secured in the same covenant; they are bought with the same price of Christ's blood, and are justified by the same righteousness; they are all equally the sons of God, and so heirs of the same heavenly inheritance; and are all made kings and priests unto God, and there is but one kingdom, one crown, one inheritance for them all; and the holiness and beatific vision of the saints in heaven will be alike; and therefore they should be heartily affected to one another here on earth, who are to be partners together in glory to all eternity. So the Jews say F16, that in the world of souls, all, small and great, stand before the Lord; and they have a standing alike; for in the affairs of the soul, it is fit that they should be all (Mywv) , "equal", as it is said ( Exodus 30:15 ) , "the rich shall not give more".