● Rom 8:15 . . For you have not received a spirit of slavery again to fear; but you have received a spirit of adoption
The spirit of adoption serves a very special purpose. It imparts to adoptees the heartfelt bond that enables adopted children to feel the love, and the friendship, and the security feelings that natural-born boys and girls feel with their birth parents.
Sometimes adopted children feel somewhat inferior to natural-born children; and I think that's likely a very normal reaction. The spirit of adoption is no doubt intended to prevent those kinds of negative thoughts and insure that everyone in God's home feels just as equally welcome and belonging as Christ.
Let me show you something that's so astounding that it's nigh unto impossible to believe is really a fact.
There's a couple of Greek verbs translated "love" in the New Testament. One of them is agapao (ag-ap-ah'-o) which is an impersonal kind of benevolence, i.e. it's civil, but not necessarily affectionate. Everyone practices agapao from time to time by means of courtesy, sympathy, charity, and kindness, etc.
An example of agapao is located in John 3:16 where it's said that God loved the world; but that doesn't necessarily mean He likes the world. In point of fact, we know from Gen 6:6-7 that God would be content were the world dead and gone.
The other verb is phileo (fil-eh'-o) which always, and without exception, expresses fondness, attachment, and affection. An example of phileo is located in John 16:27 where Jesus stated:
"The Father himself loves you because you have loved me and have believed that I came from God."
It's very difficult for those of us brought up in dysfunctional homes, or the foster system, or an orphanage to believe that anybody, anywhere, feels the slightest affection for us. But there it is in clear type. The Father is attached, bonded, and strongly sentimental with everyone to whom John 16:27 applies.
Knowing that you're loved is quite a bit different than feeling loved. In time, the spirit of adoption makes the Father's paternal feelings just as real for people brought into His home as they are for Christ. Pretty amazing.