Galatians was written to members of the Body of Christ.
His point is that they had fallen from the understanding of grace and who they were in Christ that he had left them with.
It is this that he now finds himself having to travail in birth AGAIN that said understanding might be formed in them again.
Galatians 1:2 And all the brethren which are with me, unto the churches of Galatia: 1:3 Grace be to you and peace from God the Father, and from our Lord Jesus Christ, 1:4 Who gave himself for our sins, that he might deliver us from this present evil world, according to the will of God and our Father: 1:5 To whom be glory for ever and ever. Amen. 1:6 I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel: 1:7 Which is not another; but there be some that trouble you, and would pervert the gospel of Christ. 1:8 But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. 1:9 As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.
Galatians 3:1 O foolish Galatians, who hath bewitched you, that ye should not obey the truth, before whose eyes Jesus Christ hath been evidently set forth, crucified among you? 3:2 This only would I learn of you, Received ye the Spirit by the works of the law, or by the hearing of faith? 3:3 Are ye so foolish? having begun in the Spirit, are ye now made perfect by the flesh? 3:4 Have ye suffered so many things in vain? if it be yet in vain. 3:5 He therefore that ministereth to you the Spirit, and worketh miracles among you, doeth he it by the works of the law, or by the hearing of faith? 3:6 Even as Abraham believed God, and it was accounted to him for righteousness. 3:7 Know ye therefore that they which are of faith, the same are the children of Abraham.
Galatians 4:8 Howbeit then, when ye knew not God, ye did service unto them which by nature are no gods. 4:9 But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? 4:10 Ye observe days, and months, and times, and years. 4:11 I am afraid of you, lest I have bestowed upon you labour in vain. 4:12 Brethren, I beseech you, be as I am; for I am as ye are: ye have not injured me at all.
4:17 They zealously affect you, but not well; yea, they would exclude you, that ye might affect them. 4:18 But it is good to be zealously affected always in a good thing, and not only when I am present with you. 4:19 My little children, of whom I travail in birth again until Christ be formed in you, 4:20 I desire to be present with you now, and to change my voice; for I stand in doubt of you. 4:21 Tell me, ye that desire to be under the law, do ye not hear the law? 4:28 Now we, brethren, as Isaac was, are the children of promise.
4:31 So then, brethren, we are not children of the bondwoman, but of the free.
And so on...