Addressing an estimated 20,000 people gathered in St. Peter's Square, Pope Benedict continued a series of audience talks about prayer in the letters of St. Paul.

Focusing on St. Paul's assertion that it is the Holy Spirit that enables people to pray and to address God as "Abba, Father," the Pope said, "the absence of one's father or the lack of a father's presence in a child's life today is a big problem that always makes it difficult to understand fully what it means to say that God is our father."

From the beginning of Christianity, believers adopted Jesus' form of addressing God as father, especially in the Lord's Prayer, the Pope said.

"Christianity is not a religion of fear, but of trust and love for the Father who loves us," he said.

Pope Benedict acknowledged that "critics of religion have said that speaking of God as 'father' is simply a projection" of our own longings and desires, but the Gospel shows that the opposite is true, because "Christ shows us who the father is and what a true father is, so that we can understand and also learn what true fatherhood is."

Jesus demonstrated that God is love, he said, and when people pray to God as father, they enter into "a cycle of love" that offers them support, but also correction and guidance.

The assertion that human beings are made in God's image and likeness means that he is their father, the Pope said. "A line in the Psalms always touches me when I pray it: 'Your hands made me and fashioned me.'"

"Every one of us, every man and woman, is a miracle of God, desired by God and personally known by him," he said.