And because ye are sons, God hath sent forth the Spirit of His Son into your hearts, crying, Abba, Father. – Galatians 4:6

“Because ye are sons,” means, -because the time appointed of the Father is come, and you are of age, and no longer under tutors and governors. In our minority we are under the schoolmaster, under the regimen of ceremonies, under types, figures, shadows, learning our ABCs by being convinced of sin; but when faith is come we are no longer under the schoolmaster, but come to a more free condition. Till faith comes we are under tutors and governors, like mere boys, but after faith we take our rights as sons of God. The Jewish church of old was under the yoke of the law; its sacrifices were continual and its ceremonies endless; new moons and feasts must be kept; jubilees must be observed and pilgrimages made: in fact, the yoke was too heavy for feeble flesh to bear. The law followed the Israelite into every corner, and dealt with him upon every point: it had to do with his garments, his meat, his drink, his bed, his board, and everything about him: it treated him like a boy at school who has a rule for everything. Now that faith has come we are full grown sons, and therefore we are free from the rules which govern the school of the child. We are under law to Christ, even as the full-grown son is still under the discipline of his father’s house; but this is a law of love and not of fear, of grace and not of bondage. “Stand fast therefore in the liberty wherewith Christ hath made us free and be not entangled again with the yoke of bondage.” Return not to the beggarly elements of a merely outward religion but keep close to the worship of God in spirit and in truth, for this is the liberty of the children of God. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1435.cfm