When the Israelites are about to enter the Promised Land, they are told to utterly destroy the holy things of the people they are about to displace. They are told to drive out the inhabitants, not simply to conquer them.
God is not talking about vengeance here. He is talking about purity. If they allow the holy places of the pagans to remain, they will become what is legally known as "an attractive nuisance." People are drawn to the forbidden. Tell a child not to go beyond a fence, and you can't turn your back but what he's trying to scale it, or burrow beneath it, or unlock the gate.
The Israelites are told to destroy the images and idols of the pagans. To demolish their places of worship. If they don't do this, they will be tempted just to see what goes on there. To look at the idols and images as pieces of art. And they are apt to be seduced by what they see, and their worship of God will be adulterated.
In some sense, you can't be both tolerant and pure. If you harbor people of differing beliefs, you must be strong and pure in what you believe, or you are apt to be led into believing half-ruths and innuendo.
God requires an undivided heart. If you give Him anything less, you are subject to judgment. He is a jealous God because He loves us. Not because he is a petty tyrant. He knows our propensity to be lead astray by curiosity, by idle wondering.
Help us to drive out anything that would hinder our fellowship with You. Show us the idols and high places in our lives so that we may destroy them in order to serve you better and draw nearer Your throne.
In Jesus' most precious name.