Just ask yourself, "what would Jesus do"? Call someone a hypocrite, snake, that they are of their father the devil?
But Paul, who was Jesus speaking to? It wasn't another brother. These people were trying to kill him. If everyone on here called each other by these names what do you think would happen? A big BAN.
Well, I don't think He called the Pharisees hypocrites, snakes, and that they are of their father the devil because they were out to kill Him. He called them those things because they were:
Shutting the kingdom of heaven in men's faces. (Mat. 23:13-14)
Making converts twice as much a son of hell as the converters themselves are. (Mat. 23:15)
Claiming that swearing by the temple is nothing, but claiming that swearing by the temple's gold is everything. (Mat. 23:16-22)
Obeying the minutiae of the law (such as giving up a tithe) but neglecting the important facets (such as justice, and mercy) - metaphorically straining out a gnat but swallowing a camel. (Mat. 23:23-24)
Being shallow - metaphorically cleaning the outside of the cup and dish but leaving the inside full of greed and self-indulgence. (Mat. 23:25-26)
Hypocrisy - appearing righteous but actually being full of wickedness, metaphorically like whitewashed tombs, beautiful on the outside, but full of dead men's bones. (Mat. 23:23-27)
Claiming that they would have behaved better than their forefathers - even though they build and respect the tombs of those who murdered the prophets. (Mat. 23:29-36)
Mind you this didn't apply to every Tom, Dick and Harry in Judea. But exclusively to the Priesthood.
The thing is. What's to keep a false, bad, misguided, delusional, wacky etc. teacher from comparing himself to Christ and those pointing out his error as Pharisees?
This is usually how it goes. I think the true divider is, if someone truly thinks someone to be a false, bad, misguided, delusional, whacky etc. teacher and points it out. Or if someone is purposefully maliciously attacking someone's character, reputation etc. Now the false, bad, misguided, delusional, wacky etc. teacher will of course accuse them of this.
And this is where God comes in: If someone is purposefully maliciously attacking someone's character, reputation etc. then they are of course under His judgment. However, if someone truly thinks someone is a false, bad, misguided, delusional, wacky etc. teacher and points it out, then they are either correct or simply mistaken. I listen to pastors and teachers on the radio all the time who point out those who they consider to be false, bad, misguided, delusional, wacky etc. teachers. But it's not being done out of malice or hatred or false motives, it's being done because that person sincerely believes the person they are addressing on the airwaves is false, bad, misguided, delusional, wacky etc. teacher.