Wherefore thou art no more a servant. In the Christian Church slavery no longer exists, but the condition of the children is free. In what respect the fathers under the law were slaves, we have already inquired; for their freedom was not yet revealed, but was hidden under the coverings and yoke of the law. Our attention is again directed to the distinction between the Old and New Testaments. The ancients were also sons of God, and heirs through Christ, but we hold the same character in a different manner; for we have Christ present with us, and in that manner enjoy his blessings.

Wherefore - In consequence of this privilege of addressing God as your Father.
Thou art no more - You who are Christians.
A servant - In the servitude of sin; or treated as a servant by being bound under the oppressive rites and ceremonies of the Law; compare the note at Galatians 4:3
But a son - A child of God, adopted into his family, and to be treated as a son.
And if a son - Entitled to all the privileges of a son, and of course to be regarded as an heir through the Redeemer, and with him. See the sentiment here expressed explained in the the note at Romans 8:17.

Thou art no more a servant - Thou who hast believed in Christ art no longer a slave, either under the dominion of sin or under obligation to the Mosaic ritual; but a son of God, adopted into the heavenly family.
And if a son, then an heir - Having a right to the inheritance, because one of the family, for none can inherit but the children; but this heirship is the most extraordinary of all: it is not an heirship of any tangible possession, either in heaven or earth; it is not to possess a part or even the whole of either, it is to possess Him who made all things; not God's works, but God himself: heirs of God through Christ.

Wherefore thou art no more a (h) servant, but a son; and if a son, then an (i) heir of God through Christ.
(h) The word "servant" is not taken here for one that lives in sin, which is appropriate for the unfaithful, but for one that is yet under the ceremonies of the Law, which is proper to the Jews.
(i) Partaker of his blessings.

Wherefore thou art no more a servant,.... This is a benefit resulting from adoption, and the manifestation of it to the children of God, and supposes them to have been formerly servants; as whilst in a natural state they were the servants of sin, the vassals of Satan, slaves to the world, and the lusts of it, and in bondage to the law; but now being declared to be the sons of God under the witnessings of the Spirit, they are freed from the servitude of sin, from the captivity of Satan, from the slavery of the world, and particularly from the law, and that spirit of bondage which it brought upon them, which is chiefly designed; and from which they are delivered by the spirit of adoption, enabling and encouraging them to cry "Abba", Father; so that they are now no more under the former servile spirit, the spirit of a servant,
but a son; whose spirit, state, and case, are vastly different from those of a servant: the servant has not that interest in his master's affections as the son has; nor that liberty of access to him; nor is he fed and clothed as he is, or shares in the same privileges he does; nor is his obedience performed in the same free generous manner, from a principle of love and gratitude, but in a servile and mercenary way; and though he may expect his wages, he cannot hope for the inheritance; nor does he always abide in the house as the son does. He that is once a son, is always so, and no more a servant: predestination to sonship is immutable; it is God's act to put any among the children, and none can put them out; the covenant of grace, in which this blessing is secured, is unalterable; union with Christ, the Son of God, on which it is founded, is indissoluble; the spirit of adoption, wherever he witnesses, abides as such. They that are the sons of God may be corrected and chastised, as they often are, in a fatherly way; but these corrections are proofs for, and not against their sonship; they may indeed judge themselves unworthy to be called the sons of God, and may be in such frames of soul as to conclude, at least fear, they are not; but still the relation abides, and ever will. They will never more be servants, but always sons. The very learned Mr. Selden (i) thinks the apostle alludes to a custom among the Jews, who allowed only freemen, and not servants and handmaids, to call any Abba, Father such an one, or "Imma", Mother such an one: but this seems to proceed upon a mistaken sense, and rendering of a passage in the Talmud (k), which is as follows, ; which he thus renders, "neither servants nor handmaids use this kind of appellation, Abba", or "Father such an one", and "Imma", or "Mother such an one"; whereas it should be rendered, "servants and handmaids, they do not call them Abba, Father such an one", and "Imma, Mother such an one"; this is clear from what follows. "The Family of "R. Gamaliel" used to call them Father such an one, and Mother such an one"; which in the other Talmud (l) is, "the family of" R. Gamaliel "used to call their servants and their handmaids Father Tabi, and Mother Tabitha"; which were the names of the servant and handmaid of Gamaliel. Rather therefore reference is had to a tradition (m) of theirs, that
"a servant, who is carried captive, when others redeemed him, if under the notion of a servant, or in order to be one, he becomes a servant; but if under the notion of a freeman, , "he is no more a servant".''
Or to the general expectation of that people, that when they are redeemed by the Messiah, they shall be servants no more; for so they say (n),
"your fathers, though they were redeemed, became servants again, but you, when ye are redeemed, , "shall be no more servants";''
which in a spiritual sense is true of all that are redeemed by Christ, and through that redemption receive the adoption of children, and is what the apostle here means.
And if a son, then an heir of God through Christ; which is another benefit arising from adoption. Such as are the children of God, they are heirs of God himself; he is their portion and exceeding great reward; his perfections are on their side, and engaged for their good; all his purposes run the same way, and all his promises belong to them; they are heirs of all the blessings of grace and glory, of righteousness, of life, of salvation, and a kingdom and glory; and shall inherit all things, and all "through Christ": he is the grand heir of all things; they are joint heirs with him; their sonship is through him, and so is their heirship and inheritance; their inheritance is in his possession, it is reserved safe in him; and by him, and with him they shall enjoy it. The Alexandrian copy, and some others, only read, "an heir through God", and so the Vulgate Latin version; and the Ethiopic version only, "an heir of God".
(i) De Successionibus ad Leg. Ebr. c. 4. p. 33. (k) T. Bab. Beracot, fol. 16. 2. Vid. Maimon. Hilch. Nechalot, c. 4. sect. 5. (l) T. Hieros. Niddah, fol. 49. 2. Vid. Massech. Semachet, c. 1. sect. 13. (m) Misn. Gittin, c. 4. sect. 4. (n) T. Hieros. Sheviith, fol. 37. 2.

Wherefore--Conclusion inferred from Galatians 4:4-6.
thou--individualizing and applying the truth to each. Such an individual appropriation of this comforting truth God grants in answer to them who cry, "Abba, Father."
heir of God through Christ--The oldest manuscripts read, "an heir through God." This combines on behalf of man, the whole before-mentioned agency, of THE TRINITY: the Father sent His Son and the Spirit; the Son has freed us from the law; the Spirit has completed our sonship. Thus the redeemed are heirs THROUGH the Triune GOD, not through the law, nor through fleshly descent [WINDISCHMANN in ALFORD]; (Galatians 3:18 confirms this).
heir--confirming Galatians 3:29; compare Romans 8:17.

Wherefore, thou art no more a servant. Because redeemed, adopted as a son, having received the spirit of adoption.
If a son, then an heir. Compare Romans 8:17. Heirs of a heavenly inheritance.
Howbeit, then. These Galatian brethren had been idolaters, and had worshiped idols which were not gods at all. At that time they knew not God, the true God, at all.
But now, after that ye have known God. Having learned the knowledge of the true God.
Or rather, are known of God. God, himself, had sought them through the gospel, and had offered them eternal life. They knew God because God had taken note of them and sent them the gospel.
How turn ye again. How can they, known of God, called from the bondage of those that are not gods (Galatians 4:8), turn back again to bondage? The bondage referred to is that of the law. They had been delivered from the bondage of idolatry, but were relapsing into another bondage.
Weak and beggarly elements. Weak, because they have no spiritual power to strengthen us; beggarly, because they have no rich promises like the gospel; elements, because they belong to a rudimentary condition, to an undeveloped state to the childhood of the race.

Wherefore thou - Who believest in Christ. Art no more a servant - Like those who are under the law. But a son - Of mature age. And if a son, then an heir of all the promises, and of the all - sufficient God himself.