What are your thoughts on calling God "Abba Daddy" or "Papa?" In reading the thoughts of others and their reason for using this phrase, I was wondering when this came about.
The phrase "Abba, Father" came about when Jesus called out to God in an hour of need before his crucifixion. "And He was saying, "Abba! Father! All things are possible for You; remove this cup from Me; yet not what I will, but what You will" (Mark 14:36). Paul also used it when describing Christians as being God's adopted children, brought out of slavery and into the arms of God's protection.
"For you have not received a spirit of slavery leading to fear again, but you have received a spirit of adoption as sons by which we cry out, "Abba! Father!" (Romans 8:15).
"Because you are sons, God has sent forth the Spirit of His Son into our hearts, crying, "Abba! Father!" (Galatians 4:6).
Abba is the transliteration of the Aramaic word for "Father." It is used to refer to God a few times in the Old Testament (Psalms 89:26; Isaiah 64:8). The second word in the phrase is the Greek word pater that means "Father." Abba does not mean "Daddy" or "Papa." The word "father" is used by children of all ages, including adult children, to refer to their male parent. This gives us an understanding of how close Jesus is to God and how we can be close, too. That is why this word is used to describe the Christians relationship with God. It is one of many aspects of how we relate to God.
The belief that the Greek word should be translated "Daddy" or "Papa" was started by a "German Lutheran New Testament scholar Joachim Jeremias, who in his 1971 text New Testament Theology explained that abba was "the chatter of a small child. . . . a children's word, used in everyday talk" and seemingly "disrespectful, indeed unthinkable to the sensibilities of Jesus' contemporaries to address God with this familiar word" (p. 67). While Jeremias did not use the word "daddy" or "papa" in relation to abba, the implication was strong and others came along to make that connection." [FactChecker].
Every source I could look up indicated that "father" was the proper translation of abba and pater, and I referenced most of my library. A search on the Internet also indicates that Joachim Jeremias was the source of this interpretation.
While there is a desire to make our relationship with God more personal, introducing informality shows a disrespect for God unless God invites us to address Him in that manner -- and He did not. It would be like being introduced to the president of your country and you slap him on the back and say, "It is good to meet you buddy boy!" It just would not go over well.
When you know two languages, saying something twice puts more emphasis on what is being said. For example, "This is very good, muy bein." (Spanish) I said the same thing twice, but it emphasizes the meaning. People also tend to say something twice when they are being emphatic. For example, when we are pleading or stressing the importance of what we are saying, we may say, "Please, please! Listen to me!" Or when Jesus talked about the truth about entering the Kingdom of God, he said, "Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God" (John 3:3).
I have a personal theory, though I can't prove it with certainty. The phrase used both the Jewish and Greek words to show that both Jews and Gentiles have one Father. Hostility between Jewish and Greek Christians can be seen in the books of Romans and Galatians. The phrase would counter the hostility. But, as I said, it is just a theory.
I hope this helps.