I have seen many kinds of arguments like this in the West. That Russia is fundamentally a Christian-European civilisation. That Russia and the West must eventually join hands to take down Communist China. I think this is a very flawed view of what Russia actually is: an Eurasian Country. Russians are actually not just all White Christians as the West always imagines them to be. There are Cossacks, Dagestani Muslims, Siberians, Kazakhs, Mongols, etc. Only in Russian films, can we see the appearance of non-White Russians actors. I don't recall one Western film about Russia that portrays any Russian minorities. Its a big misconception in the West to assume that Russia is a homogenous, white-Christian nation.
There was a time when Russia was a true Christian-European nation. That was the Russian Empire. It joined the West and Japan in carving up China. But still the West and Japan eventually betrayed Russia. The Russian Empire didn't last for more than 20 years since the Boxer Rebellion. And everytime when there are great political revolutions in Russia, ie.: The Russian Civil War of 1917, and the fall of the Soviet Union. The Western countries are always there to meddle and make the situation worse. Germany, a fellow Christian-European civilisation, waged wars on Russia twice, 1914 and 1941. I find it hilarious when German Christian fanatics expect Russia to embrace Germany instead of China.
Since the fall of the Soviet Union. What has China and West had done to Russia? Both relationships were not perfect. But Russia's relationship with the West is the most damaging. The West have been a clear and present danger to the security of the Russian state. NATO moved Eastwards, economic sanctions, wealth stripping of the Russian economy, abandonment of arms control treaties, Color Revolutions, destruction of Russia-friendly nations, promotion of Russophobia in Russia's own neighbourhood, etc. Name any of China's crimes against Russia that is anywhere nearly as bad.
The West never thinks of Russia as an equal. The so-called, European Christian alliance is joke. The West actually wants to recruit Russia, like India, and Japan to fight China and die on their behalf. That's all.
Even if the West becomes friendly again to Russia. Why should Russia only choose one side? Why can't Russia be friends to both the West and China? Putin was originally trying to pursue that. But the West never respected Russia as an equal. China did. That's why Russia trusts China far more than the West. There is no such thing as a Russian destiny to join the European Christian civilisaton club. That club means nothing to Russia, and its filled with imperialism and betrayals.