I once heard a sermon by Pastor Dick Bernal in San Francisco which opened my eyes as an adoptee. He shared that in the original Greek texts of the Bible that the words "adopted as God's children" in the book of Romans and others, could be more accurately translated as "reunited" as God's children. The prodigal son in scripture was not his Father's "adopted son", but his own flesh and blood. He ran to embrace his child who had been gone for years.
It is a beautiful comfort to know God is my true Father and I am his child. There is no need for Him to "adopt" me as we think of adoption in today's society, because I actually came from Him to begin with. So many things in this world work to separate us from the pure knowledge of God's unconditional love for us as our Father ("Abba" means Daddy) God. I'm so thankful He runs to reunite with me.
"...I will never leave you, nor forsake you." God