Joshua called God Father more than 100 times in the Book of John. He referred to God almost exclusively as Father. And this despite the fact that the Old Testament records a host of names for God, of which a short list would be: Elohim, El-Shadai, Jehovah, Yahweh, Adonai and El-Elyon. A longer list of more descriptive titles would include terms such as deliverer, rock, stone, fortress, shepherd, branch, redeemer, judge, shield, strength and king.
He often referred to God as my father, making God a personal family member which implies a loving, caring person who is interested in our well-being and personal growth. Just as our earthly fathers look after us (assuming they are good fathers) and are concerned and actively involved with our every phase of growing up, so too does our Heavenly Father concern himself with our lives.
The Son of God revealed God to us by his own relationship with his Father. He said that I and the Father are one. That is, their purposes and the working out of God’s will by the Son were one and the same. When we are so joined to the doing of God’s will then, we too, will be one with the Father. He showed us that the supreme desire in life ought to be doing the will of God.
Through the pictures and word-stories of seeds, plants growing and being harvested the Master showed the progression of the life of the believer from a young sapling to full maturity; as a healthy stalk of wheat ready to be harvested or as a tree producing fruit year after year. What the parables Joshua taught revealed over and over was a life of growth.
When the Son of Man taught his disciples how to pray, the opening line of the prayer was Our Father who is in Heaven. This was not just a way to address God, it was the most excellent way, as the apostle Paul would say.
The Hebrews saw God as the Almighty, a stern judge who was a divider of the righteous and the unrighteous; an authoritative dispenser of justice and an avenger of his people. The God that Joshua revealed was a compassionate, loving, caring, forgiving God full of mercy and kindness who was intimately acquainted with all our ways.
But now, O LORD, You are our Father, we are the clay, and you our potter; and all of us are the work of Your hand.
The Fatherhood of God is mentioned in the Hebrew scriptures: Isaiah says God O Lord our father, our redeemer, and Jeremiah and Malachi make mention of God as Father of the house of Israel, but the God that Joshua referred to was the Father of all humanity. This was new, or at the very least it was a far-expanded revelation of God than anything heard on earth up until that time.