A number of times, I have had Mormons--including friends and family--tell me that Jesus would never tear down another religion. He wasn't mean to people like that. He didn't tell people they were wrong in their beliefs, or warn people of those who lead others from truth.
Quite the opposite!
I understand why Mormons say that Jesus wouldn't do this. Jesus was emphatic about showing love to people, and Mormons wish to cling to this aspect of him so that they can believe their faith should not be attacked--that good people who follow Christ wouldn't do this, so it must be a "bad" person saying things against the church, and therefore what they say is invalid. Sometimes, though, it is more loving to show people why they are wrong. Revelation 3:19 says "Those whom I love I rebuke and discipline." Jesus and his apostles showed this type of love often, and often with harsh or firm words, either in rebuke to people or in warning believers about who to watch out for and fight against. Here's some examples in the New Testament.
Matthew 3:7 But when he saw many of the Pharisees and Sadducees coming to where he was baptizing, he [John the Baptist] said to them: “You brood of vipers! Who warned you to flee from the coming wrath?
Matthew 16:6 “Be careful,” Jesus said to them. “Be on your guard against the yeast of the Pharisees and Sadducees.”
Matthew 23:15, 23, 25, 27, 29 “Woe to you, teachers of the law and Pharisees, you hypocrites!"
Luke 11:39 Then the Lord said to him, “Now then, you Pharisees clean the outside of the cup and dish, but inside you are full of greed and wickedness.
Matthew 7:21 “Watch out for false prophets. They come to you in sheep’s clothing, but inwardly they are ferocious wolves."
Ephesians 6:12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms.
2 Peter 2:1 But there were also false prophets among the people, just as there will be false teachers among you. They will secretly introduce destructive heresies, even denying the sovereign Lord who bought them—bringing swift destruction on themselves.
1 John 4:1 Dear friends, do not believe every spirit, but test the spirits to see whether they are from God, because many false prophets have gone out into the world.
The Bible shows a theme of correcting and revealing wrong teachings and wrong teachers. From the beginning, sin was punished and false teachings were revealed as such. God does not destroy sinners the first time they sin, like he could, out of love...but neither does he not tell them that they're wrong, because letting them continue to believe wrongly would be an extreme disfavor.
Acts 20:25 “Now I know that none of you among whom I have gone about preaching the kingdom will ever see me again. 26 Therefore, I declare to you today that I am innocent of the blood of any of you. 27 For I have not hesitated to proclaim to you the whole will of God."