My understanding was OT Israel was a theocracy and there was no separation between church and state. Our tithes and offerings are a kind of tax in our church family. We can be thankful that we receive tax write-offs for them when in reality it is supporting church work.  Of course, we expect taxes to be used for social security, disabilities, and welfare (in a different set-up that doesn't encourage dependence). Bible direction provides principles rather than specifics as locations and times change.