What Kind of God is This?

Joshua 6 is the story of Jericho's fall at the feet of Israel, and the next chapter is the fatal account of Achan. At the end of the account are these two verses (7v25-26)
"Joshua said, 'Why have you brought this trouble on us? The LORD will bring trouble on you today.'
Then all Israel stoned [Achan], and after they had stoned the rest [of his family and livestock], they burned them.
Over Achan they heaped a large pile of rocks, which remain to this day.
Then the LORD turned from his fierce anger.
Therefore that place has been called the Valley of Achor/Trouble ever since."

It's the description of God and his reaction to the situation that startles me. It is so unlike Jesus. What kind of God is this?

Some background to the story: God is bringing Israel into the promised land, they've just crossed the boundary river called the Jordan - now they are in enemy territory. Either they destroy the inhabitants of the land, or the inhabitants will rise up and destroy them. It is a very violent, tribal-oriented, black and white culture. Either you are for me or against me, no middle ground. So Jericho is the first stop, and since it is the first city to be conquored, and God is going to give them the city (all they have to do is walk around it...basically), the Israelite army is to "devote" the city to God. This means that all possessions (silver, gold, jewelery, etc) are to go to the temple treasury, and all living beings are to be destroyed. It all sounds so bloody and brutal. What kind of God is this?

Achan, in his plundering of the city, took some of the possessions for himself, something that God expressly forbid - there was no confusion of the issue. He confessed that he coveted the items and took them anyway. Either he didn't think God would notice, he didn't think God would really do anything about it, or he was stupid.

God did notice, and God did care, and he did do something about it. God became fiercly angry.

Was God justified in getting fiercly angry with Achan? How does this compare with Jesus getting fiercely angry with the money-changers in the temple?

Is it okay that our God gets fiercly angry?

What happens if he gets fiercly angry with us?