The context is human beings in whom the Spirit of God dwells. Jesus, as a human being, having the Spirit of God without measure, was still considered to be part of the Godhead. These verses, verse 14 especially, show that if God begins to give His spirit to those who obey Him (Acts 5:32), they also become the sons of God! This is also seen in I John 3:1-2.
John W. Ritenbaugh
The Nature of God: Elohim
The Holy Spirit is the power of God—not a personage, entity, consciousness, or part of the Godhead or a trinity. The Bible speaks of the Spirit as the power or mind of God, the power of love and of a sound mind. It emanates from Him and thus can be said to be "poured out" (Titus 3:5-6), "breathed" (John 20:22), and used to "fill" (Acts 2:4) and "anoint" (Acts 10:38).
Martin G. Collins
The Holy Spirit
Other Forerunner Commentary entries containing Romans 8:12: