(CNN) -- Pope Francis rang in his first Christmas at the Vatican with a Christmas Eve Mass preaching a message of love and forgiveness.
"On this night, let us share the joy of the Gospel. God loves us. He so loves us that he gave us his son to be our brother, to be light in our darkness. To us the Lord repeats, 'Do not be afraid,' ... And I, too, repeat, do not be afraid,'" the Pope said.
"Our Father is patient. He loves us, he gives us Jesus to guide us on the way which leads to the promised land. Jesus is the light who brightened the darkness. Our Father forgives always. He is our peace and light."
He called on the throngs gathered at St. Peter's Basilica on Tuesday to cast aside hatred.
"God is light and in him there is no darkness at all. Yet on the part of the people, there are times of both light and darkness, fidelity and infidelity, obedience and rebellion, times of being a pilgrim people, and times of being a people adrift," the Pope said. "In our personal history, too, there are both bright and dark moments, lights and shadows. If we love God and our brothers and sisters, we walk in the light. But if our heart is closed, if we are dominated by pride, deceit, self-seeking, then darkness falls within us, and around us. Whoever hates his brother -- writes the Apostle John -- is in the darkness; he walks in the darkness, and does not know the way to go, because the darkness has blinded his eyes."
Before the Mass, pilgrims gathering in Vatican City told CNN they were excited to celebrate with the Pope.
"We want to share this special moment with a person who is a beloved person, and we appreciate all he's doing," one woman said.
Nine months into his papacy, much has been made of the Pope's reforms, among them more scrutiny at the Vatican bank, changes to the church's bureaucratic structure, and a commission to deal with the abuse of minors.
And while this year's Christmas liturgy remains the same, experts say we should expect the unexpected.
"He tends to be a surprise, because he does things that are normal, but are very abnormal in terms of the papacy," said Gerard O'Connell, a Vatican analyst. "He brought three homeless men into where he is living to have breakfast with him on his birthday. ... I suspect we will see something else again over the Christmas period."
The festivities began on Saturday, with the Pope's Christmas message to the Curia. He urged the church's governing body to avoid gossip and to focus on service.
And then he practiced what he preached, spending three hours at a local hospital bringing Christmas cheer to sick children.
There were a record number of requests to attend this year's Christmas Eve Mass.
On Christmas Day, tens of thousands of pilgrims are expected to flood St. Peter's Square to hear his message to the world.
"People are listening to him, because he's speaking in a language that's not Vaticanese," O'Connell said. "He's speaking the language of ordinary people."