“Our” comes with “Father”. In calling God Father we are speaking first and foremost about Jesus’ relationship to God, not our own. The important thing isn’t that this is a male word, Christians have always believed that God is greater than any human conceptions of gender, but that Father attempts to describe the family relationship that is part of God’s own life. We can’t say “Father” without remembering the Son; we can never know the Father unless the Son reveals Him to us.
God is not some great basket we can fill with any warm fuzzy thoughts we choose, nor some amorphous something that is the mystery left over after we have explained everything else in life. God has a face and name. We see that face in Jesus, and so we can call God, Abba, Father; not as a literal description, but a metaphor to refer to our relationship to God, a relationship that can also be explored with other metaphors like “mother” or “friend.”
We don’t call God “Father” because we have had certain positive experiences with our biological fathers and, therefore, project those upon God. Rather, all human fathers are measured, judged, and fall short on the basis of our experiences of God as Father. When we pray “Our Father”, we’re challenging the status quo of human relationships, just as calling the church our family challenges the limitations of the human family; our first family is not our biological family, but those with whom we pray “Our Father.”
Praying “Our Father” teaches us to look beyond our families and see our home in God’s family, a family that comes from all nations, races, and cultures, and which we call the Church, people with whom we ought, by the world’s standards, to be strangers, and yet we are all part of God’s family the body of Christ. When we pray “Father”, we’re asking God to help us to demonstrate this relationship to God in our daily life.