The Hebrew term yir’ah is rendered fear or terror. It denotes some awesome or terrifying thing and it is used in reference to our perspective of God, promoting respect, reverence and piety. From the Greek term phobos we get phobia, meaning fear and terror. We dread the thing that provokes terror. Phobic reactions are visceral, automatic and instinctive. Paul amplifies the picture of appropriate fear before God by adding the descriptor, trembling, from the Greek tromos. This is not merely cognitive or psychological. This is not a literary device to augment God’s awfulness [awe-fullness] – here the whole being, physical and spiritual, is before God, trembling. The experience with God is to be incredibly ‘awful.’ The word now carries an almost exclusively negative connotation; because we have such difficulty with contradictory notions. And yet, God is never understood without an embrace of his radical extremes – he can be known, he can’t be fully known; he forgives, he judges; he is gracious, he is exacting in his edicts; he is holy and must deal with sin and the sinner, he loves the sinner; he is merciful, he is a God of wrath. We dismiss one side of the continuum and end up with half-a-god. The side we have dismissed in the last few decades, has been to isolate the anger of God, to deny that he judges, to make him soft and cuddly – all about love.
Joachim Jeremias set forth the idea of ‘abba’ as ‘daddy’ equating it with ‘child-babble.’ Almost immediately, the proposal was challenged. James Barr published an article entitled “Abba Isn’t ‘Daddy’” which appeared in the Journal of Theological Studies. Jeremias retreated from his claim that “abba” connoted “daddy” in the world of etymology, acknowledging that the word was one of respect for seniors and teachers. But he continued to assert that infants did in fact make such a sound, and we that we proudly claim the infant’s ‘dada’ as a term of intimacy; so he claimed abba as an endearing term for God. With the etymological foundation gone, his claim was wishful conjecture, completely disconnected from Biblical language studies. But the idea still persists.
And with it has now come a pervasive one-sided understanding of God. And that is now contributing to the lack of spiritual health in the Church. Intimacy, closeness, warmth? Yes, but not without deep respect!
 James Barr, “‘Abba’ Isn’t ‘Daddy’ [Journal of Theological Studies, 1988]; See also: Geza Vermes, Jesus in the World of Judaism , pp. 41, 2.