Why do people get angry in discussions of religion and politics? May I suggest an answer? Because they have something significant at stake in both cases; and because they have little sense of effective control in either case. When people have something significant to lose and feel like there is little they can do about whether they will lose or not, anger is the most typical response.
Politics is one of those areas in which everyone knows that effective control is not in our hands. No one can tell where the glitches are going to come from that will deny us our desires, and no one likes to hear someone across the table tell them that those glitches are the best public policy. The bottom line is: will I get what I want out of this policy? If the answer is yes, there is a certain smugness that comes along. If the answer is no, anger is the reaction. Smugness and anger are not a good mix, so many people simply decide to not discuss politics with anyone except people of the same persuasion.
Religion is the other issue that raises the ire of many. Why? Because religion deals with eternally significant issues. Heaven and Hell. And because most people do not have any real sense of security in their religious setting. Most folks are religious without any real sense of a personal, and secure, relationship with God. And, most people reject what I have just written. Most would claim to have both a personal and secure relationship with God.
But, there are two ways to tell whether the claim to security is real or a self-deception. The first way is to see how our emotions react to religious discussion. If we are angry because someone doesn't agree with us, it is because we are insecure. A secure person, whose relationship with God has created love for others in his heart, is not angry with those who disagree.
The second way is to see how our emotions react when we are faced with the possibility of death. If we are terrorized by the thought, it is because we are not secure in our relationship with God. If the gospel of Jesus is true, we have the forgiveness of our sins through faith in His death and resurrection. If we are afraid of death, it is because we do not believe heaven is our home. So, those who fear death are insecure. Therefore, religious discussion is very likely to raise the specter of angry debate--because angry people are insecure people.
How about it? Do you have a secure confidence of eternal life because of Jesus Christ, or do religious conversations make you ill at ease and angry? The Word of God says that the only way to please God is to trust Him (Hebrews 11:6), and insecurity is certainly not trust. God's Word to you is that He will give eternal life to you if you will put your trust in His promise of life through Jesus (John 3:16). His promise stands good no matter which translation you read it out of.