JMNT(i)
5 to the end that He could (or: would) buy out (ransom; redeem; reclaim [from slavery]) those under [the] Law – so that we could and would receive and take away into possession the placing in the condition of a son (or: the deposit of the Son; the setting in place which is the Son; the constituting as a son; the placing in the Son).
6 Now, because we exist being (are presently and continuously) sons, God sends off His Son's Spirit (or: the Breath-effect, which is His Son) as an emissary into our hearts, repeatedly crying out (habitually calling out or exclaiming in an inarticulate cry; even: screaming, shrieking [verb also means: croak, as a bird]), "Abba (Aramaic: = Dad, or, Daddy!), O Father!"
7 So that, you are (you exist being) no longer a slave, but rather, a son, and since a son, also an heir (a possessor and an enjoyer of the distributed allotment) through God [other MSS: God's heir through Christ].