Catholic News Service reports that the pope made the comments during a visit to a Rome parish that serves a predominantly immigrant population, including the city's Filipino community.
In a sermon, the pope focused on what has become a running theme of his pontificate: the importance of divine love.
"Only God's love can change from within the existence of the person and, consequently, the existence of every society, because only his infinite love liberates from sin, the root of every evil," the pope said.
That same love is reflected in the sacrifice of Christ, who came with the concrete goal of saving souls, he said.
"Christ came to tell us that he desires all of us in heaven and that hell, which isn't spoken about much in our time, exists and is eternal for those who close their hearts to his love," the pope said.
The important thing is to understand that "the true enemy is attachment to sin, which can lead us to the failure of our own existence," he said.
The pope emphasised that God also offers mercy and forgiveness for sinners. While it's true that God represents justice, he is first of all love, he said.
"If he hates sin, it's because he loves each person infinitely," he said.
As a theologian, the pope wrote about hell on several occasions. In the 1968 book, "Introduction to Christianity," he described hell as a state of existential abandonment, "the loneliness into which love can no longer reach."
In "God and the World," a book-length interview in 2000, he said the church reminds people of heaven and hell in order to underline that "there is a responsibility before God, that there is a judgment, that human life can either turn out right or come to disaster."
The Catechism of the Catholic Church defines hell as "the state of definitive self-exclusion from communion with God and the blessed."
God's love is great, but hell 'exists and is eternal,' pope says (Catholic News Agency, 26/3/07)
LINKS (not necessarily endorsed by Church Resources)
Hell (Catholic Encyclopaedia)
Hell (Catechism of the Catholic Church)
27 Mar 2007