This holiday season, I wish every American would take a moment to reflect on one of our most precious freedoms — the right to real religious freedom — and understand that it wouldn’t be possible without the separation of church and state.

Religious freedom means the right to join the house of worship of your choice. It means the right to change your mind and join another. It means the right to follow your own spiritual path outside of formal religious denominations. It means the right to reject all religions.

That freedom, as crucial as it is, isn’t possible without the separation of church and state. When religion and government are combined, there’s no true freedom of conscience. Where the government has a favored religion, all others are second class.

Religious liberty depends on the separation of church and state. In fact, it rests securely upon what Thomas Jefferson in 1802 called the “wall of separation between church and state.”

It has become fashionable lately to take potshots at Jefferson’s wall and the entire concept of church-state separation. Supreme Court justices have done it, and so have politicians and some academics. U.S. Sen. Jeff Sessions, R-Ala., President-elect Donald Trump’s nominee to be attorney general, has called church-state separation an “extra-constitutional doctrine” and “a recent thing that is unhistorical and unconstitutional.” (Jefferson and James Madison would be surprised to hear that.)

None of these critics, however, has put forth a coherent vision of religious freedom that doesn’t involve a distance between church and state. Nations that don’t have separation tend to fall into one of two categories: nightmarish theocracies favored by Iranian mullahs and the Islamist extremists of ISIS or the established churches that still cling to life in some European nations. The first is a recipe for oppression, and the second results in devitalized churches that do little more than provide pomp and ceremony for the state.

The United States found a third way, a better one. A colonial-era pastor, Roger Williams, was among the first to see what was possible. Weary of the stifling church-state union of Puritan Massachusetts, Williams set off on his own and founded a city based on complete religious liberty for all. He called it Providence, and it was a place where all were free to worship as they saw fit, guided by conscience.

Some years later, Jefferson and Madison made another great leap forward. Jefferson wrote a bill to end the established church in Virginia and guarantee all residents the right to worship. Madison pushed it through the legislature and made it law.

Madison later took those principles with him during the writing of the Constitution. Known as the Father of the Constitution and one of the primary authors of the First Amendment, Madison ensured that the government would have no power to meddle in the private religious affairs of the people.

“There is not a shadow of right in the general government to intermeddle with religion,” Madison once observed. “Its least interference with it, would be a most flagrant usurpation.”

The assertion that church and state could survive and indeed prosper without mutual dependency was a radical idea. No nation had ever tried it before. Yet it proved to be an amazing success. The results speak for themselves: The United States is a nation of great religious and philosophical diversity. Hundreds of denominations flourish here, all supported through the voluntary contributions of their members. Around the globe, people who live under the iron heel of government-enforced orthodoxy look at our system of separation with envy.

Some would have us give up this gift today for the promise of government “help” for religion. Some would cash it in for a by-rote, generic prayer in public schools or the right to erect a nativity scene on the steps of city hall for two weeks in December. Some today believe the separation of church and state has outlived its usefulness or that it somehow suppresses faith.

They couldn’t be more wrong. For evidence, look around you. The great diversity of American religiosity is as close as the streets of your town. It’s evident among your neighbors. It’s likely present in your own family.

Sometimes the best gift is one you’ve had all along. Maybe you don’t think about it much, and perhaps you even take it for granted a bit — but it is there for you, every time you want and need it.

Separation of church and state plays that role, safeguarding, and indeed making possible, our nation’s commitment to religious freedom. All I want for Christmas this year is for Americans to acknowledge that.