Matthew 19:4
4 And He answered and said to them, “Have you not read that He who made[a]them at the beginning ‘made them male and female,
Jesus asks the Pharisees a seemingly innocent question "Have you not read?," but a deeper look into the historical context shows this to be quite a sarcastic mocking question. For someone to become a Pharisee they had to memorize the first 5 books of the bible! so it was obvious that they had read it, they had studied it, memorized it, they had read it tons of times. Jesus was sarcastically mocking the Pharisees here.
Matthew 23:33
33 Serpents, brood of vipers! How can you escape the condemnation of hell?
Jesus is calling them Serpents and brood of vipers!
There is a difference of course, between the type of mocking and insults Christ is using and the type of mocking and insults that are commonly used today, an article I found on Tektonics sums up Christianity insults and mocking quite nicely.
Many ancient societies (and we shall see below, certain modern social groups) engage in a process known as challenge-riposte. The scene of such processes is public venues in which two persons or groups have competing honor claims: "...the game of challenge-riposte is a central phenomenon, and one that must be played out in public." [42] The purpose is for each party to try to undermine the honor, or social status, of the other in an exchange that "answers in equal measures or ups the ante (and thereby challenges in return)."
In the Gospels, Jesus "evidences considerable skill at riposte and thereby reveals himself to be an honorable and authoritative prophet." Many of these challenges are clear, but some are so hidden to us that they need exposition.
There is a difference between the type of satire and mocking used in challenge-riposte and simply insulting people for the sake of pride or to get back at someone who insulted you first. I particularly like the following parts (which I broke up into separate sections) of the article as it is quite analogous to fighting.
There are certain people who has no desire whatever to discuss the truth-claims of the Christian faith. His sole goal, so it seems to me, is quite simply to ridicule Christianity and Christians .... There is no kindness in his approach, and he seems to show none of the 'caution' standard in careful inquiry and exposition.
Everyone now and then (more often than not it seems) in a gym you will encounter someone that is 'outwardly' seeking to join the gym and learn to fight, but inwardly they are just seeking to prove to themselves or their crew (they usually try to bring their friends along) that they're tougher and stronger and better than these 'wussy trained fighters.' They have no intent to learn, they have no intent of bettering themselves as a person or a fighter, their only intent is to appease their own ego and pride.
What to do with such a one? If you play the nice guy, you're likely to get swarmed, not by any irrefutable arguments, but rather, by a veritable skyscraper of excess and inflammatory verbiage. And unfortunately, there are those, on both sides of the argument, who are persuaded by such things. We are humans, not computers, and a show of confidence or arrogance does, to some, seem to equate with being the victor.
Continuing from the example above, that person(henceforth named "the bum") goes through the same process that everyone else goes through, they have to spar with one of the top 3 fighters in the gym. Now what is the fighter to do against the bum? quite analogous to the above article, if the fighter plays nice with the bum, he will get swarmed, not by any actually effective fighting technique but simply because the fighter is playing nice, coddling the bum, not trying to hurt the bum, but this runs the risk of undermining the gym, the fighters own skill, and even worse promotes the bums own fighting style, ego and pride as superior to the gym and one of the 3 top fighters.
So what does the Christian apologist, in dealing with such as these, do? He fights a spark with a blow torch. Just as, when climbing a mountain, even though the goal is to reach the top as quickly as possible, and therefore, so it would seem, only moving upward in a straight line is the most conducive activity for achieving this end, we often find that it is actually more expedient to, at certain moments, to go to the left or right (for instance, when there is a boulder or stream immediately in front of us); so too, the Christian apologist, out of the love for Love, is at certain times warranted in using sarcasm and satire.
What should the fighter do in dealing with these bums? he must beat them, soundly, not to appease and lift his own ego and pride, but to simply show that his fighting style, his way, his tao, is superior while bums fighting style is the inferior one, his fighting style is closet to the truth, the bums fighting style is not. Just as the article states the Christian uses sarcasm and satire out of love for Love, rather than loving his own ego and pride, the fighter delivers each punishing blow to the face, not to selfishly justify his selfish desires, but out of love for his gym, his coach, and the tried and true effectiveness of the fighting style.
That is why when someone genuinely wants to learn about Christianity(or anything for that matter) I do not insult or sarcastically mock them, I do not treat them like the people that "simply seek to ridicule Christianity and Christians," I try(my best) to do what I can to help them learn. Similarly when it comes to the gym, when someone genuinely wants to learn how to fight, the top 3 boxers do hit them with 100% strength, they do not go all out on them, they do not treat them like a bum, but rather gently(yes, in fighting there is a gentleness) test their current level of fighting while helping them learn.