Here is an excerpt:
When God adopts men and women into his family he insures that not only may they have the rights and privileges of his sons and daughters but also the nature or disposition consonant with such a status. This he does by regeneration — he renews them after his image in knowledge, righteousness, and holiness. God never has in his family those who are alien to its atmosphere and spirit and station. Regeneration is the prerequisite of adoption. It is the same Holy Spirit who regenerates who is also sent into the hearts of the adopted, crying ‘Abba Father’. But adoption itself is not simply regeneration, nor is it the Spirit of adoption — the one is prerequisite, the other is consequent.