The most important thing to worry about in this world is where your soul is going after you die. After death, it is too late to change your mind. Only during life may you be saved. The only way to be saved is to hear the true gospel. You need to know that you are a sinner, and that if you die unsaved, you will be sent to Hell to pay for your sins. Everyone deserves Hell, for we all have sinned. Even the smallest sin is deserving of an eternity in Hell. God, however, chose to love some of us; not because of anything we did, because we are all the same, horrible sinners; but because he simply wanted to. So, since those people whom he loves are still sinners deserving of Hell, he sent his Son Jesus to go to the earth, live a perfect, sinless life, and die on the cross that our sins may be put on Him and that He may suffer our Hell for us, that we may be with God in Heaven for all eternity. And if any one dies without being saved, that means God does not love them, and is not willing to save them from their sins, and will send them to Hell for all eternity. The way the Lord saves people is by taking the gospel, which I just told you, using it to put fear in the heart of going to hell, causing that fear to make you realize you are a sinner and your only hope is if God chooses to love you, and then pleading before God to have mercy on you. Then God will save you. God will never deny anyone that comes to him pleading for salvation, because no one can come to him unless he is first called, which is what is happening when you start to fear the wrath of God in Hell. So back to the initial debate, if you simply compromise by being silent on this matter when someone you are talking to believes differently, and what they believe will not get them to Heaven, then it is your responsibility as a Christian to tell them the truth, and may that truth be used by God to save their soul. If you choose to simply be silent and that person goes to Hell for the heresy they believed, then their blood is on your hands for not attempting to give them the gospel, which could have saved them if the Lord willed.
I believe modern day religion causes more harm than good. We have the financial and secular influences to inflict change without the mentioning of religion. HOWEVER, bringing religion into an argument is completely legitimate. We're all on debate.Org, how could we be against bringing any mode of argumentation into a debate? This makes no sense.
Historically, religion started many of the social welfare programs that modern culture has adopted and turned secular. To ignore this is a complete intellectual fallacy.
In a non-supervised debate, you can say whatever you want, and it doesn't matter if it's something stupid to say or not. And, the last time I checked, religion is something you can physically bring up. With that being said, as a very conservative Christian I believe that bringing your religion into a debate, no matter who it is with or what they believe, is perfectly okay and have never hesitated to do so.
Anything is permitted in the heat of an intense argument. Attacking somebody's personal beliefs is never a considerate thing to do, but sometimes it is okay if they did that to you as well. Religion shouldn't have to play a major role in everyday life, but it really does to a lot of people. When you really want to hit home, then bring up religion, but be prepared for your opponent to become angered.
Generally speaking, most arguments do not require a religious stance. In those scenarios, there is no reason to bring up religion. Because there are so many different perspectives surrounding religion, it becomes inappropriate and even inflammatory to bring religion up in everyday arguments. Unless your argument specifically calls upon the concept of religion, it's better to just leave religion out of it.
The other person says something you disagree with and you decide to speak your opinion. They ask you why you feel that way about the topic. Should you bring your religion into the argument? I say no. It's a pointless effort anyway, as they believe something other than you and most likely won't agree just because you do. Not to mention, they might take your religious stand as an insult to their religion, and they might think that you feel your religion is superior. Leave the religion out of it, and let people believe whatever they want. Find another way to express your opinion.
The only reason people use religion is when they are against gender identity or a person's sexuality, why should religion be the one thing that controls all controversy? We can define our choices on our own, if you want to make a relevant opinion, don't use things that aren't related to the subject. Don't argue about sandwiches and be like "Oh, it's god's will for you to eat this and not that!" If the religious topic is relevant, then, yes you can bring it up. However, don't bring religion into personal affairs, that isn't the point, and people should be able to make choices of their own.