The Philippine president, who recently sparked outrage for calling God stupid, has courted new controversy in his largely Roman Catholic country by saying he will resign if anybody can prove that God exists.

President Rodrigo Duterte, who has had a thorny relationship with the church, questioned anew in a speech late Friday some of the basic tenets of the Catholic faith, including the concept of original sin, which he said taints even innocent infants and can only be removed through baptism in a church for a fee.

'Where is the logic of God there?' Duterte asked in a speech at the opening of a science and technology event in southern Davao city.

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Filipino President Rodrigo Duterte questioned some of the basic elements of Catholicism in a speech on Friday

The 73-year-old leader said that if there's 'one single witness' who can prove, perhaps with a picture or a selfie that a human was 'able to talk and to see God,' he will immediately resign.

Duterte, however, suggested that there must be a God or a supreme being that prevents billions of stars and celestial bodies from colliding in a frequency that could have long threatened the human race.

Last week, he was slammed, including by some of his political allies, for calling God 'stupid' in another speech, with one Catholic bishop calling him a 'psychopath.'

Duterte lamented in that speech that Adam and Eve's sin in Christian theology resulted in all the faithful falling from divine grace.

'Who is this stupid God? This son of a bitch is then really stupid,' he said last week. 'You were not involved but now you're stained with an original sin ... What kind of a religion is that? That's what I can't accept, very stupid proposition.'

Opposition Sen. Antonio Trillanes IV shot back at Duterte by describing him as 'one evil man' and his remarks as 'very much consistent with the deceitfulness, heartlessness and ruthlessness of his policies.'

Duterte said he would resign if there was a single witness to prove the existence of a God

Presidential spokesman Harry Roque has defended his remarks, saying Duterte has the right to express his opinion on religion and cited the president's previous disclosure that he was once sexually abused by a priest.

Duterte on Friday recalled that experience, when he said he and other students were fondled by a foreign Jesuit priest, who has since died.

Amid the criticisms, officials have arranged a meeting between Duterte and the head of the largest association of Catholic bishops on Monday.

Filipino bishops opened an annual conference in Manila Saturday and were expected to address Duterte's tirades when they conclude their meeting on Monday.

Some Catholic bishops have been critical of Duterte's brutal crackdown against illegal drugs, which have left thousands of suspects dead in reported clashes with the police, along with his vulgar and expletives-laden speeches.

He once called Pope Francis a 'son of a bitch' for sparking a monstrous traffic during a 2015 visit in Manila that trapped Duterte for hours.