Celibacy is central to the priesthood, Pope Benedict XVI said, amid concerns from some that the requirement has somehow contributed to the wave of abuse scandals rocking the Church.
"For the world where God is not present, celibacy is a great scandal... that should disappear," the Pope said.
He was answering one of the questions put to him by one of the 15,000 priests gathered for a vigil in St Peter's square at the Vatican to celebrate the end of the Year for Priests.
Priest celibacy is "an act of faith and fidelity" towards God and a way to anticipate on earth the pureness of the afterlife, said the Pope.
This understanding of celibacy was often obscured by "the secondary scandals of our failings and sins," he added - an oblique reference to the priest paedophilia revelations that have rocked the Church in recent months.
Pope Benedict said he would pray for God to "free us from the secondary scandals".
Since late last year, the Roman Catholic Church has been embroiled in a series of sex abuse scandals across Europe and the Americas, prompting harsh criticism of the Vatican's handling of the issue.
Some senior Catholic clergymen and intellectuals have called for a new discussion of the issue of priest celibacy when considering the possible causes behind the sex abuse scandal.
But the Pope said criticism of celibacy "can come as a surprise at a time in which not getting married is increasingly in fashion".
He added: "Marriage is the natural, biblical form of being man and woman."
Should it disappear, he said, "the foundation of our culture would be destroyed".
Cardinal Claudio Hummes, the prefect for the Congregation of the Clergy, introduced the Pope thanking him for what he "has done, does, and will do for all priests, including those that are lost".
Cardinal Hummes in April urged the 400,000 priests around the world to flock en masse to the Vatican to show their support for Pope Benedict XVI against "unjust attacks" over his handling of clergy sex abuse.