I have given you the Spirit of adoption so you can call Me Father.
Romans 8:15 (WEB)
For you didn’t receive the spirit of bondage again to fear,
but you received the Spirit of adoption, by whom we cry, “Abba! Father!”
The most precious gift that God could give us is Himself. The Holy Spirit, which is called the Spirit of adoption or the Spirit of sonship, is the very Spirit of God Himself. The third person in the Trinity is also referred to as the Spirit of the Father and the Spirit of the Son. The Bible says that we have received the Holy Spirit as a deposit to guarantee our inheritance. (2 Corinthians 1:22)
His very presence in our lives is the sign that we belong to God. We have now been born again and are God's children and part of His amazing family. The very Spirit of the living God resides in us and bears witness with our own spirit that we are heirs of God and joint-heirs with Jesus. The only appropriate response that we could possibly have is to cry out from the core of our being the words 'Abba, Father!' (Romans 8:15-17).
'Abba' is an Aramaic word which was the common language that Jesus spoke to the people with. It is the most simple way that a child can call out to their father. In English terms, it would be like us calling out to our papa or daddy.
Romans 8:15 tells us that because we have the spirit of Sonship living in our hearts, we can call Almighty God our Papa! There is no greater gift that He could have given to us, than the gift of His own life that now lives right in the center of our being.