Updated for more detail answer as requested.
It appears that this SE site doesn’t like straight forward answers such as mine.
Original Ans provided below:
At the start of any conversation regarding one's faith, just state in the beginning it's a personal matter and not open for discussion. The only reason you are getting feedback, both positive and negative, is that you have willingly engaged in a conversation about your faith.”
I have been asked to respond in more detail as to the background behind the answer that would make the answer more appropriate or other details other viewers deem necessary to be an appropriate answer.
When first looking at this question, I thought about my past 40 years of interactions with co-workers, friends, associates, etc. Why have I not encountered the type of discussions described by OP. I have worked and associated with hundreds of people of all races, cultures, religion, beliefs, traditions. etc. In the majority of these environments, I was in the minority. During all this time, none of the discussion has ever went so far that the other person attacked my belief or I felt the necessity to defend it.
In looking at the details of the OP question:
A question was asked on the Buddhism stack that garnered a well written answer from the Buddhist point of view, comparing Jesus and Buddha to highlight similarities. However, I'm interested in a general answer, rather than a Buddhist theological answer.
Why is the question being reposted on this SE? There were many general answers provided for the original site posted on the Buddhism stack. What was the issue with the general answers provided on the original post?
How can this person avoid or prevent this conflict? Is it avoidable? If you practice a religion or spiritual faith, and christian friends belittle the object of your faith, and say those who practice your beliefs shall go to hell, what's the best way to avoid that situation or end it?
My original answer as posted, stated how to avoid the situation. I treat all personal questions on religion, belief, culture as personal and not for discussion. On question about culture, I may explain some history, significant of the culture, etc. If I fill that the other person wants to start a debate, or makes observations that appear to question my belief or culture, tradition, etc., I just end the conversation that it is not open for debate and walk away. I have closed conversations like this many times without it becoming an issue.
I'm not looking for ways to win an argument, but a way to resolve and move forward with as little conflict as possible. Ideally avoid it completely.
I have some friends who are Christian that I can't avoid the subject with. We used to see each other very often for some events. Normally those are friends of friends. Examples of the unpleasant feedback I commonly receive include things like "Buddha is Satan", "Buddha is in hell" and "All Buddhist shall go to hell". There are many other examples and by - for example - searching YouTube, you'll find more than enough examples.
The only reason you cannot avoid the subject, is that you are a willing participant in the discussion, and have shown your willingness to debate the issue. No one just walks up to you and make a statement, “Buddha is Satan”, unless you have been debating the question or is known to like to debate one’s belief. If someone approaches you in a work environment to discuss religion, and you stated you do not want to discuss your belief, that person would be reported as creating a hostile work environment if they were to try to continue the discussion.
I am looking for some efficient and effective response to avoid this unfruitful conversation and prevent more unpleasant conversation that won't benefit anyone. It's better to have a compassionate discussions instead.
This original statement in the question shows that the poster wants to debate the issue, He just call it “compassionate discussions”. How do we know that the original poster did not make a statement or point that cause the response?