Answer not a fool according to his folly lest thou also be like unto him.
This is an important verse to remember. Be careful what questions you answer, and how you answer them. Particularly questions about God and His Word. Of course, Christians should speak of Christ. They are to be ready to give an answer to every person that asks them of the reason of the hope that is in them. But they are also to be wise as serpents and meek as doves.
In a past job, my colleagues used to talk about every subject under the sun. No topic was off limits, not even religion. They used to ask me all sorts of questions about Christianity, and I used to try and answer them all, tying myself up in knots in the process. One of my colleagues once admitted to me that he only asked me questions about Christianity to make fun of it. I naively thought my colleagues were interested, and never stopped to question their motives.
Every situation is different, wisdom from God is needed in every conversation we have. Sometimes it is wise to think about the motive of a question. Don’t be afraid to question the questioner if necessary. It might be a series of questions that start off seeming serious but then degenerate into joking. Maybe you want people to like you, so you are just glad they are talking to you. But real friends’ care. Friends that don’t care about you are no friends at all.
However lonely we may be, we have not even begun to suffer the loneliness Jesus suffered. All His disciples forsook Him and fled. He was forsaken of His Father whilst suffering in agony on the cross. Why did He do it? Because He is the friend of sinners.
One there is above all others, Well deserves the name of friend: His is love beyond a brother’s, Costly, free and knows no end. [Hymn 133, Gadsby's Hymn Book]
Remember David’s prayer; Set a watch, O LORD, before my mouth; Keep the door of my lips. Incline not my heart to any evil thing. Pray that God would give you wisdom in all situations and remember not to answer a fool according to his folly, lest you also become like him.
Bible References [click links below to read references]
 Psalm 141:3,  Luke 21:15.