They are children--that is, ignorant and unable to take care of themselves; because they do not know what they are. St. Paul tells us what they are. That they are all God's offspring, though they know it not. He likens them to young children, who, though they are their father's heirs, have no more liberty than slaves have; but are kept under tutors and masters, till they have arrived at years of discretion, and are fit to take their places as their father's _sons_, and to go out into the world, and have the management of their own affairs, and a share in their father's property, which they may use for themselves, instead of being merely fed and clothed by, and kept in subjection to him, whether they will or not. This is what he means by receiving the adoption of sons. He does not mean that we are not God's children till we find out that we are God's children. That is what some people say; but that is the very exact contrary to what St. Paul used to say. He told the heathen Athenians that they were God's children. He put them in mind that one of their own heathen poets had told them so, and had said, 'We are also God's offspring.' And so in this chapter he says, You were God's children all along, though you did not know it. You were God's heirs all along, although you differed nothing from slaves; for as long as you were in your heathen ignorance and foolishness, God had to treat you as His slaves, not as His children; and so you were in bondage under the elements of the world, till the fulness of time was come. And, then, God sent His Son, born of a woman, born under a law, to redeem those who were under a law--that is, all mankind. The Jews were keeping, or pretending to keep, Moses' law, and trying to please God by that. The heathens were keeping all manner of old superstitious laws and customs about religion which their forefathers had handed down to them. But heathens, and indeed Jews too, at that time, all agreed in one thing. These laws and customs of theirs about religion all went upon the notion of their being God's slaves, and not his children. They thought that God did not love them; that they must buy His favours. They thought religion meant a plan for making God love them.