And what agreement - (συγκατάθεσις sugkatathesis). Assent, accord, agreement. what putting or laying down together is there? What is there in one that resembles the other?
The temple of God - What has a temple of God to do with idol worship? It is erected for a different purpose, and the worship of idols in it would not be tolerated. It is implied here that Christians are themselves the temple of God, a fact which Paul proceeds immediately to illustrate; and that it is as absurd for them to mingle with the infidel world as it would be to erect the image of a pagan god in the temple of Yahweh. This is strong language, and we cannot but admire the energy and copiousness of the expressions used by Paul, “which cannot,” says Bloomfield, “be easily paralleled in the best Classical writers.”
With idols - Those objects which God hates, and on which he cannot look but with abhorrence. The sense is, that for Christians to mingle with the sinful world; to partake of their pleasures, pursuits, and follies, is as detestable and hateful in the sight of God as if his temple were profaned by erecting a deformed, and shapeless, and senseless block in it as an object of worship. And, assuredly, if Christians had such a sense of the abomination of mingling with the world, they would feel the obligation to be separate and pure.
For ye are the temple of the living God - see this explained in the notes on 1 Corinthians 3:16-17. The idea is, that as God dwells with his people, they ought to be separated from a sinful and polluted world.
As God hath said - The words here quoted are taken substantially from Exodus 29:45; Leviticus 26:12; Ezekiel 37:27. They are not literally quoted, but Paul has thrown together the substance of what occurs in several places. The sense, however, is the same as occurs in the places referred to.
I will dwell in them - (ἐνοικήτω enoikētō). I will take up my indwelling in them. There is an allusion doubtless to the fact that he would be present among his people by the Sechinah, or the visible symbol of his presence; see the note on 1 Corinthians 3:16-17. It implies, when used with reference to Christians, that the Holy Spirit would abide with them, and that the blessing of God would attend them; see Romans 8; Colossians 3:16; 2 Timothy 1:14.
And walk in them - That is, I will walk among them. I will be one of their number. He was present among the Jews by the public manifestation of his presence by a symbol; he is present with Christians by the presence and guidance of his Holy Spirit.
And I will be their God - Not only the God whom they worship, but the God who will protect and bless them. I will take them under my special protection, and they shall enjoy my favor. This is certainly as true of Christians as it was of the Jews, and Paul has not departed from the spirit of the promise in applying it to the Christian character. His object in quoting these passages is, to impress on Christians the solemnity and importance of the truth that God dwelt among them and with them; that they were under his care and protection; that they belonged to him, and that they therefore should be separate from the world.