The Catholic Church insists on modesty, for example. You won't find an outright ban on nudity, because what is considered modest can change depending on culture. However, if you are trying to remain chaste by avoiding pre-marital sex & masturbation, it is not difficult to see how sexually explicit images make that difficult. In fact, pornography is specifically singled out as a crime against chastity.
> 2523 There is a modesty of the feelings as well as of the body. It protests, for example, against the voyeuristic explorations of the human body in certain advertisements, or against the solicitations of certain media that go too far in the exhibition of intimate things. Modesty inspires a way of life which makes it possible to resist the allurements of fashion and the pressures of prevailing ideologies.
> 2524 The forms taken by modesty vary from one culture to another. Everywhere, however, modesty exists as an intuition of the spiritual dignity proper to man. It is born with the awakening consciousness of being a subject. Teaching modesty to children and adolescents means awakening in them respect for the human person. [1]
> 2354 Pornography consists in removing real or simulated sexual acts from the intimacy of the partners, in order to display them deliberately to third parties. It offends against chastity because it perverts the conjugal act, the intimate giving of spouses to each other. It does grave injury to the dignity of its participants (actors, vendors, the public), since each one becomes an object of base pleasure and illicit profit for others. It immerses all who are involved in the illusion of a fantasy world. It is a grave offense. Civil authorities should prevent the production and distribution of pornographic materials. [2]
You are conflating nudity and porn when they are two different things, and as far as nudity is concerned, focusing only on whether it is okay according to Christianity to be naked, rather than the other question more relevant to this story, which is whether it is okay according to Christianity to see someone else (who may or may not be Christian themself) be naked.
No, I didn't conflate anything. My post specifically covered that pornography is banned, while nudity may be permissible if it does not offend modesty.
> Most of religions forbid people to be naked / see other people naked? Please, list some of them, as I'm having a hard time finding which ones do this.
You decided to respond with a point about pornography. Either you conflated nudity and pornography, or you responded with something unrelated to the question. I assumed the former as that seemed to me to be the more charitable explanation, but if the latter was the case instead, I apologise for the incorrect assumption. Instead, let me ask you: why did you feel it relevant to bring up pornography in response to that question?
The bulk of his reply was not about pornography. He specifically stated the Catholic Church has no outright ban on nudity, but quoted two paragraphs from the Vatican about "resist[ing] the allurements" of "voyeuristic explorations of the human body" in advertising or other media that "go too far in the exhibition of intimate things".
If advertising material qualifies, nudity in films qualifies.
For all practical purposes, Catholicism is an example of a religion that forbids nudity. Depictions of nudity that the church would find acceptable, online or in popular media, are rare enough that a concerned Catholic would be justified in avoiding all nudity out of caution.
> 2523 There is a modesty of the feelings as well as of the body. It protests, for example, against the voyeuristic explorations of the human body in certain advertisements, or against the solicitations of certain media that go too far in the exhibition of intimate things. Modesty inspires a way of life which makes it possible to resist the allurements of fashion and the pressures of prevailing ideologies.
> 2524 The forms taken by modesty vary from one culture to another. Everywhere, however, modesty exists as an intuition of the spiritual dignity proper to man. It is born with the awakening consciousness of being a subject. Teaching modesty to children and adolescents means awakening in them respect for the human person. [1]
> 2354 Pornography consists in removing real or simulated sexual acts from the intimacy of the partners, in order to display them deliberately to third parties. It offends against chastity because it perverts the conjugal act, the intimate giving of spouses to each other. It does grave injury to the dignity of its participants (actors, vendors, the public), since each one becomes an object of base pleasure and illicit profit for others. It immerses all who are involved in the illusion of a fantasy world. It is a grave offense. Civil authorities should prevent the production and distribution of pornographic materials. [2]
[1]: http://www.vatican.va/archive/ccc_css/archive/catechism/p3s2... [2]: http://www.vatican.va/archive/ccc_css/archive/catechism/p3s2...