Summarize:

If you are trying to make a good impression, this may not be the time to bring up your firmly held beliefs. Without the benefit of knowing the stances of those present, you run the risk of inadvertently offending someone with your strongly held opinions. Job interviews, joining a new social group, or being introduced to a friends or coworkers family are good examples of when it's best to keep strong opinions to yourself until you know the parties better. By joining a group designed to bring like minded people together, you won't have to worry so much about whether your opinion will offend others, but be mindful of the language you use. Your choice of tone and language may affect how your message is received. While all of the members may share similar core beliefs, there is probably great variation in how members choose to express their beliefs. You will usually only need to be extra careful in your word choice the first few meetings. After you become more comfortable with the members, you will likely fall into a natural feeling communication pattern. Friends will tolerate your strong opinions better than others. They are also very likely to argue with those opinions. This is generally a healthy exchange, but remember to always be respectful. Neither of you will likely be greatly swayed by the argument, so you don't want to have damaged the relationship by using abusive language. Focus on using the word I, rather than you, to have an amicable disagreement. If you happen to find yourself in a group of people you know to hold strong opinions opposite of yours, you might decide to keep your opinion to yourself. You don't always have to have a say.You can choose to just be an observer. If it is very important to you to share your opinion, even in these circumstances, consider forming a bond with a single member.You can then have a fair exchange between the two of you. If you do address the rest of the group at some later time, you'll know you have at least one supporter.
Keep the conversation light in a group of people you don't know. Share respectfully in groups of like minded people you don't know well. Express your opinions to your friends freely, but remember you care about these people. Choose your battles wisely.