Exactly the opposite of what the Bible teaches.
Turn the other cheek
You might note Jesus Himself, too, "Woe to you, Scribes, and Pharisees, hypocrites! For you travel land and sea to make a single convert, and when you do, you make him even more a child of Hell than yourselves."
Or the nice phrase "You tithe dill and mint and cumin, but you have neglected the weightier matters such as justice and mercy; these you ought to have done without neglecting the others."
or "For you bind heavy loads on mens' backs which they are incapable of carrying, but you do not lift as much as a single finger to help them."
Or driving the moneychangers and those who sold animals for sacrifice out of the temple, with a whip of cords.
You might want to read up from someone other than an SJW or a Muslim about what instigated the Crusades.