Hey N.drew!
Might I suggest that a fallen, imperfect, dysfunctional sinner (all of us) cannot achieve the required mark of perfect holiness so as to earn or deserve adoption as a holy son of God.
If this was possible Jesus died for nothing.
A legal transaction takes place where the believer's sin or dysfunction is imputed to Jesus, and Jesus' holiness (and righteousness) is IMPUTED to the believer. The persons Paul addressed as "the holy ones" were all sinners - their holiness was IMPUTED.
(Romans 3:20) . . .Therefore by works of law no flesh will be declared righteous before him, for by law is the accurate knowledge of sin.
(Romans 3:22-24) . . .For there is no distinction. For all have sinned [are dysfunctional] and fall short of the glory of God, and it is as a free gift that they are being declared righteous by his undeserved kindness through the release by the ransom [paid] by Christ Jesus.
(Ephesians 2:8-9) . . .By this undeserved kindness, indeed, YOU have been saved through faith; and this not owing to YOU, it is God’s gift. No, it is not owing to works, in order that no man should have ground for boasting.
(Acts 13:39) and that from all the things from which YOU could not be declared guiltless by means of the law of Moses, everyone who believes is declared guiltless by means of this One.
(Galatians 3:11) Moreover, that by law no one is declared righteous with God is evident, because “the righteous one will live by reason of faith.”