God is not a human body
Male and female are bodily realities in the created world. God made human beings in his image, and Genesis says that image is reflected in both male and female (Genesis 1:27). That means women are no less able than men to reflect God's character, worth, and calling.
Yet God himself is not a creature with a human body or biological sex. Jesus teaches that God is Spirit (John 4:24). He isn't limited by the physical categories that describe us. So the simplest answer is that God is neither male nor female in the human, biological sense.
God is a Spirit: and they that worship him must worship him in spirit and in truth.
Why does the Bible call God Father?
The Bible's usual personal name for God is Father. Jesus teaches his followers to pray to their Father in heaven (Matthew 6:9), and he speaks of a unique relationship between the Father and the Son (John 5:19). This is not casual wording or a claim that God has a male body. It tells us something true about God's personal relationship, authority, love, and faithfulness.
Christians therefore normally use the names Scripture gives: Father, Son, and Holy Spirit. These names help us receive God as he has made himself known, rather than remaking him according to our preferences. Still, calling God Father must never be used to suggest that men matter more to God than women.
After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name.
Scripture also uses motherly images
God's fatherhood contains no lack of tenderness. Through Isaiah, God compares his faithful care to a mother's deep concern for her nursing child (Isaiah 49:15). Jesus also compares his longing to gather Jerusalem's people to a hen sheltering her chicks (Luke 13:34).
Those pictures do not rename God as Mother, but they do show that qualities often associated with mothers, such as nurture, compassion, and fierce protection, belong perfectly to God. He is not a larger version of a human father. He is the Creator whose goodness is reflected, in different ways, by faithful women and men.
Can a woman forget her sucking child, that she should not have compassion on the son of her womb? yea, they may forget, yet will I not forget thee.
What about Jesus?
Jesus became fully human as a male Jewish man. His birth, life, death, and resurrection happened in a real human body, not as an appearance or metaphor (Luke 2:7; John 20:27). So it is accurate to say Jesus was male during his earthly life and remains the risen, incarnate Son.
But Jesus' maleness does not mean only men can know God or represent his image. In Christ, the divisions that people use to rank one another do not determine anyone's standing before God (Galatians 3:28). Both women and men are invited to come to the Father through the Son, and to grow in the likeness of Christ.