James Madison, together with Alexander Hamilton and John Jay, wrote essays in favor of the Constitution called the Federalist Papers. These essays were written under the pseudonym "Publius" to provide the authors anonymity.

Both Madison and Jay, along with Jefferson and Franklin, were members of the committee that drafted the Declaration of Independence.

Based on my research, the topic of "Religious Freedom" was not a major theme within the Federalist Papers.

I have included the below essay by Matthew J. Franck (Source: Roots of Liberty – Religious Freedom) because there is a large segment of the conservative wing of the Republican party which looks to the Federalist Papers as part of its' originalist/texturalist interpretation of the Constitution, Amendments, Supreme Court decisions, and other legal issues.