Verse 18. "Will be a Father unto you" - I will act towards you as the most affectionate father can act towards his most tender and best beloved child.
"And ye shall be my sons and daughters" - Ye shall all be of the household of God, the family of heaven; ye shall be holy, happy, and continually safe.
"Saith the Lord Almighty." - kuriov pantokratwrĘ The Lord, the Governor of all things.
Earthly fathers, however loving and affectionate, may fail to provide for their children, because every thing is not at their disposal; they may frequently lack both the power and the means, though to will may be present with them; but the Lord who made and who governs all things can never lack will, power, nor means. The promise is sure to the children; and the children are those who take the Almighty for their God. For the promise belongs to no soul that is not separate from sinful ways, works, and men; those who touch the unclean thing, i.e. who do what God forbids, and hold communion with unrighteousness, can never stand in the endearing relation of children to God Almighty: and this is most forcibly stated by God himself, in these verses, and in the beginning of the following chapter, the first verse of which should conclude this.
To the Jews the promises were originally made; they would not have God for their God, but would work iniquity. What was the consequence? God cast them off; and those who were joined to iniquity were separated from him. "Then said God, Call his name Lo-ammi; for ye are not my people, and I will not be your God." Hos. i. 9. The Jews were therefore cast off, and the Gentiles taken in their place; but even these, under the new covenant, are taken in expressly under the same conditions as the apostle here most fully states. Those who apply these words in any other way pervert their meaning, and sin against their souls.