First of all, let me start by saying that I do think that in order for our students to truly understand Hispanic culture, religion needs to be a piece of the puzzle. So many practices and perspectives of the culture are directly influenced by the beliefs of not only Catholicism, but of the indigenous cultures that preceded the arrival of the Spanish to the New World. To me, there is a clear distinction between teaching ABOUT something and teaching students to actually DO or BE something. Just as History teachers who teach about the Holocaust and the beliefs of Hitler are not encouraging students to practice Nazism, we are not trying to convert students to Catholicism just because we discuss the beliefs that they hold.
It is definitely possible to teach about religion in a way that enhances student understanding and perspective and does not get you (the teacher) in trouble. In 15 years of teaching in public schools, I have taught elements of religion as culture each year. I have never received a complaint from a student, parent, or administrator. Hopefully these tips will help you to teach the way you know you should without having to fear doing that.
Tip #1 - Give a Disclaimer - It is not a bad idea to tell students prior to the lesson that there will be certain religious elements mentioned. Tell them that these things are only being mentioned to help them understand the perspective of the Hispanic people and the reasons behind what they do. Make it clear that the lesson is in no way meant to devalue other religions or beliefs that people in the room may hold.
Tip #2 - Offer Students an Opportunity to Express their Concern - Tell your students that if they think the fact that religion will be discussed will make them uncomfortable or would be a concern for them or their families to please come and talk to you. This will allow you to find out ahead of time who may find a problem with your lesson and contact parents to discuss it directly prior to the lesson.
Tip #3 - Be Careful with Your Pronouns - Remove your personal religious beliefs from the conversation, whether they are similar or different than the ones you are explaining. It is important to dissociate yourself from the religion. Do not make statements that start with "I" or "We" as these will give students the impression that you are speaking about your own beliefs rather than that of the Hispanic people. Instead, begin statements with phrases like "According to the Catholic religion..." or "Many Hispanics believe...".
Tip #4 - Preview Materials - If you will be showing a video on a holiday, a song, or even a lesson. Stay true to your word and choose materials that only share religious information with the direct goal of helping students understand the perspectives of Hispanic culture. Materials that share religious opinions that do not directly relate to the matter at hand should probably be avoided.
If you are looking for some holiday materials that address religion in a way that would be suitable for a public school environment, here are a variety of lessons that you can look through.