Mark 14:36 “And he said, Abba, Father, all things are possible unto thee; take away this cup from me: nevertheless not what I will, but what thou wilt.
Although God was referred to as our Father in the Old Testament, Jesus’ frequent use of this title brought a whole new understanding of our relationship with God. Jesus referred to God as His Father, and He spoke of God as being our Father as well. This infuriated the religious Jews of Jesus’ day who considered it blasphemy to call God their Father, because they understood that to mean they were equal with God.
We are instructed to call God our Father, revealing the kind, gentle, loving nature of our God. The term “Abba” is an affectionate term that a young child calls his father, which corresponds to our term “daddy.” It is a term used to express intimacy and affectionate fondness. It removes the idea of God as a strict judge and carries the image of Him as a loving Father who cares, understands, and is our best friend. “Behold what manner of love the Father hath bestowed upon us, that we should be called the sons of God” (1 Jn. 3:1).
We are sons of God by adoption. Jesus was the Son of God by nature. As Jesus said to the Jews, ye are of your Father the devil (Jn. 8:44; Eph. 2:3).
However, Jesus purchased us and made us adopted sons of God. This is different from our modern definition or concept of adoption where by you choose a child who is not of your lineage and then legally placing him into your family. Adoption means to be placed into a position of Sonship. This is the ancient Oriental understanding of that term.
This position of Sonship implies that we have been placed into a Son. We are sons in the Son. Being located in Christ implies that :
WHAT HE IS , WE HAVE BEEN MADE
WHERE HE IS, WE ARE
WHAT HE HAS, WE HAVE
The word children is the word Teknon which speaks of being issued out of God as your source, as the species of God and this shows us indeed that God is our Father.
We are not just heirs, we are joint-heirs with Christ. To think that we share equally with the one who has inherited everything God is, and has, is beyond comprehension.