Yeah, translations need to take into account changes in writing style over the centuries in addition to changes in language.

Here's the joke in "modern English":

Instead of joining the state's church, I propose instead the following. I will buy a flag, a uniform, a gun, and one of those battery-powered toy jeeps that little kids drive around their yards. Then, with grave seriousness, I will declare my faith in God's protection, furl out my flag, and call for the members of the state's church to follow me into battle. I will then hop in my toy jeep and begin driving toward the battle field.