Having now, at the age of 43, become the first-time father of a baby girl, I have a new perspective on life filled with a whole range of different issues and questions! (Like: What will it take to get her to stop crying at 2am? And: How can I teach her to appreciate baseball and coffee?) Significantly, the fatherhood of God is a major theme in Scripture, peaking in the Gospel of John to such a great degree that Westcott could write in his commentary on John 1:18,
"τοῦ πατρός] of the Father. The choice of this title in place of God (τοῦ θεοῦ) serves to mark the limits of the revelation made through Jesus Christ. Even this was directed to one aspect (so to speak) of the Godhead. The Son made God known not primarily as God, but as the Father. At the same time this title lays the foundation of revelation in the essential relation of the Persons of the Godhead. Comp. 1 John i.2." (The Gospel According to St. John: The Greek Text with Introduction and Notes, reprint of the 1908 edition [Grand Rapids, MI: Baker, 1980) 1:29.
Westcott here is not denying that Jesus revealed God the Father as God (note the word "primarily"), as D. A. Waite infamously accused him of doing (in The Theological Heresies of Westcott and Hort as Seein in Their Own Writings). Westcott is focusing on the theological emphasis of John, which at times seems to emphasize God the Father as father even more so than (though not at the exclusion of) His identify as God. Significantly, the Gospel of John uses the word πάτηρ (patēr, "father") 138 times, one more than all three synoptic Gospels combined (at least in the TR), and patēr occurs more often in John than even Theos ("God")!
Now, John is certainly not unique in emphasizing God's role as our father and our role as his children (see, for example, Heb 12:7; 1 Pet 1:17). Nor is this theme unique to the New Testament. Isaiah 63:16, for example, connects God's fatherhood with his role as provider (v. 15) and redeemer (v. 16b). Isaiah 64:8, on the other hand, links God's fatherhood with his role as Creator. Malachi 2:10 similarly links God's fatherhood to his role as Creator, but also uses this as the grounds for a rebuke of the disunity and sinfulness of the people of Israel.
All of that creates a solid foundation for our current understanding of God as Father. Yet going back to the Gospel of John and remembering Westcott's statement, the revelation of God as Father was not complete until the incarnation of the Son. Consequently, the more we study Jesus and his relationship to the Father, the more we understand our relationship to God. And the more I understand God, the better I will understand how to raise my new daughter.