Religion often plays an important role in the culture of many countries and can be a great way for you to learn more about the country and its people. It is a good idea to research the religion(s) observed in your host country before you go abroad. Depending on where you go, religion may play a larger or smaller role than it does here in the US.
While you may be used to being part of the religious majority in the United States, your beliefs may make you a part of the religious minority while abroad. Most importantly, you want to be aware of the level of religious tolerance in your host country so you can make an informed decision on how you will practice your religion while abroad.
Students should always understand local laws, especially in regards to activities that appear as proselytizing and/or preaching. Always demonstrate respect to icons, statues, etc and by wearing appropriate clothing (for example, many churches and temples forbid shoulders or knees to be exposed). If you are unsure how to dress or act, ask!