"You don't believe like Catholics do that the Old Testament is the Word of God?"

In the Old Testament, King David (apparently inspired by Satan) took a census of Israelites, which was an offense against God.  According to the Old Testament,  God punished David by killing 70,000 Israelites by pestilence, an agonizing death.  Do Catholics really worship the God of the Old Testament who punishes one man's transgression by killing 70,000 other people?
I will bet you can not answer this in a straightforward way.  I bet your answer will be a whole lot of twisting and turning.  Or name-calling.