An important ability when witnessing is being able to tell a sincere question from an insincere one. After all, you cannot effectively reply to a question when the asker is not interested in an answer.
First, notice how a question is postulated. For example, some people ask, If God can do anything, can He create a stone so heavy that He couldn’t lift it?” The postulation, “if God can do anything,” is a presumption that He can’t do certain things, and so must not be omnipotent.
In a sense, that postulation is true: God can’t do certain things, not because of a weakness, but because of His strength. He cannot violate His perfections (also known as His attributes). God cannot sin because He is all holy; God cannot lie, because He is all Truth. God cannot do anything that would make Him less than God. But the person asking the question is usually trying to trap you into stating something God cannot do as though it would be a weakness instead of a strength.
Questions are not sincere when the person asking merely wants to reveal a flaw or mistake they already believe exists. For example, somebody will point out a difference in the genealogies presented in Matthew and Luke. They will ask, “Which genealogy is the correct one?” The presumption of error does not allow you to answer the question.
Either the person is insincere, or they do not know how to properly frame the question. You might say, “Did you want to know why there is a difference between these genealogies?” If the answer is yes, you can provide meaningful information…that one is the genealogy of Joseph, and the other of Mary.
Sometimes, in order to give an honest answer, you must reframe a person’s question, or get them to reframe it. If they’re unwilling to reframe a question so that it no longer has an underlying presumption, then the question is insincere.
Another way that you can tell whether a question is sincere is by what a person does when you answer. It’s proper for a person to acknowledge that you’ve answered a question, and to interact with that answer in some way. If they disregard your answer and go on and ask another question, you can be sure that they are not looking for answers; they are looking to stump you.
In my online witnessing I was challenged yet again over the suffering servant passage that begins in Isaiah 52:13. A Jewish man said that it could not be the Messiah; it had to be Israel, and those for whom the sacrifice was made were the Gentiles. I showed him why that interpretation could not be right. After I answered the challenge, the man treated me like I had said nothing, and went on to the next question on his list.
When someone offers me insincere questions or challenges, I just smile and say, “Now if I could answer that question for you, are you willing to receive Jesus as your Savior? Is this the one big thing that’s standing in your way?” And at that point, they usually change the subject. However, an insincere question can lead to better things.
One time I was visiting in a home and talking to the wife, who had made an inquiry. The husband was also there. He raised his voice, and said, “Well, tell me this: how can a man become God like Jesus did?” I answered by saying, “You have it backwards. Jesus the man didn’t become God. God the Eternal One became a man. Do you see anything wrong with His doing that if He chooses to do it?”
And the husband said, “No. It sure makes sense that He would become a man if He wanted us to understand Him.” That was a sincere question, even though it was not properly framed. He went on to accept Christ that night.
The husband had simply repeated a question that he had heard in a sermon from a rabbi who was speaking on the topic, “Why Jews Don’t Become Christians.” He remembered the question and asked me. He realized by my answer that the question had been an unfair one, because Christianity never taught that a man became God.
The other way of dealing with questions, if you can’t answer them, is to say, “I’ll get back to you on that.” Most of the time, your own pastor can answer the question for you. If not, you can always try Jews for Jesus. That’s what we’re here for.