Romans 8:15

Sons, οὐ γὰρ ἐλάβετε πνεῦμα δουλείας. The aorist refers to the time of their baptism, when they received the Spirit. It was not the Spirit proper to slaves, leading them again to shrink from God in fear as they had done when under the law of sin and death, but πνεῦμα υἱοθεσίας, a spirit proper to those who were being translated from the servile to the filial relation to God. υἱοθεσία is a word used in the N.T. by Paul only, but “no word is more common in Greek inscriptions of the Hellenistic time: the idea, like the word, is native Greek” (E. L. Hicks, quoted in S. and H.), see Galatians 4:5; Ephesians 1:5. The word serves to distinguish those who are made sons by an act of grace from the only-begotten Son of God: τὸν ἑαυτοῦ υἱὸν Romans 8:3, τοῦ ἰδίου υἱοῦ Romans 8:32. But the act of grace is not one which makes only an outward difference in our position; it is accomplished in the giving of a spirit which creates in us a new nature. In the spirit of adoption we cry Abba, Father. We have not only the status, but the heart of sons. κράζομεν (often with φωνῇ μεγάλῃ) is a strong word: it denotes the loud irrepressible cry with which the consciousness of sonship breaks from the Christian heart in prayer. The change to the first person marks Paul's inclusion of himself in the number of those who have and utter this consciousness; and it is probably this inclusion of himself, as a person whose native language was “Hebrew” (Acts 21:40), to which is due the double form Ἀββᾶ ὁ πατήρ. The last word certainly interprets the first, but it is not thought of as doing so: “we cry, Father, Father”.