Galatians 4

I believe Paul's teachings to the Galatians strongly teach the relationship of man with God and the potentials of man for Paul states -

"...That the heir, as long as he is a child, differeth nothing from a servant, though he be lord of all;
2 But is under tutors and governors until the time appointed of the father.
3 Even so we, when we were children, were in bondage under the elements of the world:
4 But when the fulness of the time was come, God sent forth his Son, made of a woman, made under the law,
5 To redeem them that were under the law, that we might receive the adoption of sons."  (New Testament | Galatians 4:1 - 5)

Which suggest to me that while in this life we are as children (or Paul even suggested much like servants) learning and preparing to qualify as adopted sons of the Savior and heirs of the Father.  For Paul even uses the reasoning and language -

"...because ye are sons, God hath sent forth the Spirit of his Son into your hearts, crying, Abba, Father.
7 Wherefore thou art no more a servant, but a son; and if a son, then an heir of God through Christ."  (New Testament | Galatians 4:6 - 7)

I quote from the writings of David J. Ridges -

"The term “Abba” is an intimate , familial name for our Father in Heaven. See Bible Dictionary under “Abba.” It can be translated as “Daddy” and is the same term the Savior used during His suffering in the Garden of Gethsemane when He asked that, if possible, He might not drink the bitter cup. See Mark 14: 36. An explanation of the term “Abba” is given in the Institute of Religion New Testament student manual, The Life and Teachings of Jesus and His Apostles, p. 311, as follows : “Paul suggested that through the atonement of Christ we can be adopted as sons of God, and then the Spirit shall help us cry ‘Abba, Father.’ Abba is Aramaic (a cognate of Hebrew) and carries more than just the connotation of father. It is the intimate and personal diminutive of the word father used by children in the family circle. The closest equivalent we have is papa or daddy, although neither can really convey fully the impact of the word. The point is that God is not only Father (the formal title and name), but he is also Abba, the parent of love and guidance that knows us intimately and whom we can approach without fear.”"  (Ridges, David J. (2010-10-01). The New Testament Made Easier, Part 2)