I deal on many occasions with people on the internet who want to talk about Biblical interpretations. I will do that, provided I can avoid the kinds of speculative thinking that devolves into argumentative encounters.

Often, I run into folks whose interpretation on a particular passage or doctrine is just way off track because, either the passage in question has been taken out of context, or the person I'm talking with has simply made an assumption.

It's not unusual to get a response like, "Well, that's obviously just the way you interpret it," when someone is way off the mark. That sort of reaction is usually a willfully negative one, by someone who hasn't been prepared by the Holy Spirit to accept correction. What is important in these circumstances, whether I'm dealing with a believer whose study has taken a severe Biblical left-turn, or an unbeliever, is my witness. My witness may be a part of the way the Spirit prepares their heart.

In any case, I (we) do need to be able, by the power of the Holy Spirit, to be able to give good answers to genuine questions in a way that will challenge that type of response. "That's just your interpretation," in my mind is usually just a way to avoid responsibility to God and a one on one encounter with the truth of His Word.

I have a friend who invited a couple of LDS missionaries into his home and discussed the fact that they believe in the existence of many gods, and even a convening council of gods. He opened his Bible to Isaiah 43:10 and read it to them. It reads: "10 Ye are my witnesses, saith the LORD, and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me." (Emphasis mine.)

One of the pair responded, "Well, that's just your interpretation." He responded immediately by asking them, "What interpretation? I simply read it to you."

This is what you want to be able to do these cases. Open your Bible and quote from it, using key passages. Let it speak for itself. Don't speak for it. Another example would be if someone tells you that there are many ways to heaven and that Jesus is only one of them. I hear that all the time. You could open your Bible to John 14:6 and ask, "What do you think Jesus meant when He said; ""Jesus said to him, "I am the way, the truth, and the life. No one comes to the Father except through me."" ?

Or, you could turn to Acts 4:12 and ask, "What did the Apostle Peter mean when he said, "Nor is there salvation in any other, for there is no other name under heaven given among men by which we must be saved."" You can then ask, "What do you think Peter meant by this?" or, "How else can one interpret this?" This gives them the truth of the Word and makes it necessary for them to come to terms with the bare faced statements of scripture, but be prepared to hear responses that dance around God's truth, even so.

The key though is to know and use the Bible, relying on the Holy Spirit for guidance and not on ourselves. When dealing with an obvious unbeliever, some good questions might be, "Do you have any spiritual beliefs?" or, "What do you think about spiritual things?" or, "What is the basis for your belief?" Another good question to ask would be, "Who is Jesus to you?" He, after all is what Christianity is all about, and what a person says about Him is usually very telling.

You could also ask them, "If what you believe is wrong, would you want to know that?" If they give you a "yes" answer, then you can share the gospel with them by using the Bible.