Pope Francis surprised parishioners, faith leaders and the congregation when he bowed down before everyone and confessed his sins to an ordinary priest, at St Peter's Basilica.
The pope was addressing a service, known as confession, which is a part of a ritual for reconciliation.
In his sermon, he spoke of the transforming power of Christ, confession of sins and the love of God.
"Who can say he is not a sinner? Nobody. We all are," the pope told thousands of faithful gathered at the ceremony, according to AFP.
Afterwards, he did something quite unexpected. He was supposed to enter an empty confessional booth along with 60 other priests to hear confessions from the congregation, but instead he went to another booth, knelt down before a priest, and confessed his sins for a few minutes.
The surprised priest also held the pope's hands, hearing the confession with patience.
The pope said during the sermon that confession is "not a court to judge people but an experience of mercy and forgiveness".
Following his confession, he went to another booth to listen to confessions of other faithful and cardinals for about 40 minutes.
The pope, the leading figure of the Catholic church, is supposed to confess in private, but the new move was a deviation from custom, signalling a need for revival of spiritual traditions.
Other churches around the world are also following this approach as part of the Vatican's New Evangelisation Project.
Confessions are generally heard on Good Friday morning, but Pope Francis decided to hold the event three weeks early, the AP reported.
He also spoke about key characteristics of Christian life, such as a "new self, created in God's way" and living in and sharing God's love.
"This new life lets us see the world with different eyes without being distracted anymore by the things that don't matter and that can't last for long."
The pontiff said that when hearts are renewed and "created in God's way" good behaviour follows.
"Always speaking the truth and steering clear of all lies; no stealing, but rather, sharing what one has with others, especially with those in need; not giving in to anger, rancour and revenge, but being meek, magnanimous and ready to forgive; not taking part in malicious gossip that ruins the good name of people, but looking mainly for the good side in everyone."
God's love cannot be held inside, "it's open by its very nature, it spreads and is fruitful, it always generates new love".