Eventually they made a perfect museum from Earth

To avoid possible conflicts between representatives of different religions, the Council of the Colonizers of Mars decided no one on this planet would ever build churches, mosques, synagogues and other temples in honor of their prophets, saints and founders of about two thousand modern religions. The ban extended, among other things, to Mormons who believed in a "cosmic Christ", as well as to Hindu religions, who also practiced worship of extraterrestrial energies, as well as to modern fans of the Red Planet, Black Hole, Nuclear Bomb, as well as those who worshiped Jupiter, Heaven, Sun, Milky Way, Cosmos, Kim Jong-un, Turkmenbashi, Putin and other gods.
Even disputes on the following topics were banned: the history of which nation is more ancient, richer, who is more beautiful, smarter, more educated?
Everyone had to love and know the history of the Earth as our common heritage, and such qualities and inclinations as fanaticism, intolerance and ignorance are recognized as the biggest vices, sources of any problems and troubles.
In a word, ignorance had banned at all to acces to the Mars - only well educated and balanced people were engaged in its  colonization.
Despite the fact that it was forbidden to build temples on Mars, as well as to erect statues in honor of their idols and saints, nevertheless, each person had the right to keep his faith in his heart and worship them in private.
Therefore, among the million people who settled on Mars by the middle of this century, there were many sincere worshipers of Christ, Muhammad, Krishna, Buddha, Ahuramazda, Tengir, as were those who retained in their hearts love for Lenin, Marx and even Brezhnev.
And there were a lot of fans of Albert Einstein, Elon Musk and other prominent scientists, but even they were banned.

 At first, people were indignant at this decision, saying that in this case - without temples and faith in saints - Mars will turn into the planet of the red devil, that all vices and unrest will flourish there.

But in fact, very soon, as the adaptation of the red planet proceeded quickly, more and more people began to understand that Mars gone be more and more like a heavenly place, while planet Earth, left with its two thousand religions and many temples, shrines, cults and traditions more and more resembled a hell created by people.

Naturally, in the end, almost all people moved to Mars, and only statues, temples, monuments of the past and ossified fanatics remained on Earth.

Our planet has become, as it were, a museum of our past, in which, one day, experts who have come from Mars will also be able to bring the perfect order.