Three Centuries Of Christian Atrocities

[Thumpalumpacus]

The solidification of the Party as the focal point of worship is the point @Szuchow is making, I think. Stalin even appealed actively to the OC during Barbarossa. That doesn't mean that Stalin did not appeal to the authority of Lenin's writings to justify his measures. And that also doesn't mean that millions of Soviet citizens didn't focus religious fervor upon Stalin and his secular church, the Party. They too persecuted non-believers with ferocity, and much like traditional religions reserved their deepest hatreds for breakaway sects rather than entirely different "theologies". (Many Bolsheviks hated Mensheviks more than capitalists for a long while because the Mensheviks were not just opposed, they were apostates).

You're right that it is a very complex era to study, but Soviet socialism carried a lot of religious symbolism in its secular mythos, and filled much of religion's social space in a nation, I think.

I would say that marxism-leninism was simply substitute religion, both gnostic (as marxists claimed to know the objective laws governing history) and millenarian (as communism was supposed to materialize soon, at least before Brezhnev decreed that what exists now [then] is sufficient]. Obviously it is minority position but apart from aforementioned article one can also check Raymond Aron The Opium of the Intellectuals  which is calling it political religion.

Lenin authority was bedrock of Stalin own, one could say that Stalin showed himself as faithful disciple of late prophet.

I do remember reading some quotes from Lenin about the Orthodox Church in the earliest days of the revolution.  He was going to round up the leaders of the church and execute a lot of them. because they supported the anti-Bolshevik White Russians during that era of war.  Not because of religion, but because they were seen as a danger to the Bolsheviks and the revolution.  The program was to eliminate the Church leaders, and cow the followers, and destroy any ability to effectively oppose the revolution and Communism.  It was all about realpolitik.  Stalin simply followed the established program and enlarged it.  War on the Kulaks, Trotskyites, other unreliable elements.  Minority ethnics that might support Germany over the Communists as WW2 began.  And later on, the Jews.

Any dictatorship is going to hunt out rival power-bases, but I think in this instance the Soviets decided that permitting a vestigial Church to survive would provide them one more tool of manipulation. Hence Stalin was happy to doom millions of kulaks to death but unwilling to remove their faith.

I don't think it's as simple as you seem to portray here. My apologies if I'm missing something of yours.