Patrick Henry
What you have omitted mentioning is that this was part of an historical debate in which Patrick Henry played a leading role. Patrick Henry submitted this bill to the Virginia legislature for a general tax in support of religion, which caused Madison to respond with his Memorial and Remonstrance.
Henrys views, and those of his Episcopal allies, were the views countered, and eventually defeated, by the ideas in Madisons document. The issue was controversial and heated, but Madisons side won.
So you see, it was not a principal for foundation of our national government or even the state of Virginia, but was the postion DEBATED and then REJECTED by the founders present in the Virginia state house, supported by Madison's legal and historical arguments...