Reagan and Thatcher did this.
I know for Putin it’s for propaganda purposes and he is smart enough to know a religious society thrives and uses it to his advantage.
But it’s still incredible.
Even the Chinese Communists learned that destroying one's own traditional culture makes a country (and its government) weaker, not stronger. I have no idea if Putin is a Christian, but I am certain he is absolutely sincere about promoting Orthodox Christianity's position and influence in Russia as a matter of national security against its perceived enemies.