Whether it is Jewish, Hindu, Muslim or Budhist? Is this not heresy?
Edit:
I don’t believe Ratzinger is Pope nor has there been a Pope since Vatican II
OK, first of all, let’s leave your last comment aside because this forum doesn’t allow debates about sedevacantism.
With regard to your original question, it would be best if you could point out the specific sources for your statement that the Pope attends non-catholic services. You referenced a website that is huge, and it would be nice to know exactly where to look. However, I must point out that the Most Holy Family Monastery is not the most reliable source, as they like to present little segments of information out of context, or make statements that cannot be substantiated, and use that to back up their arguments.
That being said, here are some facts to keep in mind while considering claims such as these. First, participation in non-Catholic services was formerly forbidden by canon law and this was also mentioned by various popes. However, the pope is not a subject of canon law, nor is he bound by disciplinary decrees of prior popes, as all popes share equally in the power of St. Peter.
Divine law, that is, the 1st commandment, prohibits the worship of a false god. However, not all non-Catholic worship is worship of a false god. A protestant service is directed towards the true God, but can not take place of the mass, and is therefore merely a collection of prayers, or hymns or talks or whatever. None of these things are in themselves evil, although they might contain messages that are false. Therefore, the Church might prohibit its members from participation in order to save them from being subjected to falsehoods, but a group of non-Catholics talking to/about God is not an evil that is itself contrary to divine law. The false beliefs of the participants may be contrary, but not the actual act of gathering together to pray. Do you see the difference? Therefore, a pope, who is not subject to ecclesiastical commands, might join them, provided he did say anything actually anti-Catholic.
With regard to non-Christian religions, not all of these are directed toward false, gods, either. Judaism, especially, is not, and remember that the first Christians also participated in Jewish religious functions for a time. Thus, Jewish functions are not necessarily contrary to divine law, either. As far as truly pagan religions go, sometimes they are not really directed toward a false god, but to a fuzzy understanding of the true God. It may be difficult for us to understand how each situation could or could not be a violation of the 1st commandment, but remember that the pope is actually the final authority on the interpretation and application of divine law. Therefore, we are no position to make accusations against him.
I hope this helps with your question.