This is a good example of the kind of stale marxist analysis that has stalled the left with marxist concepts. The prejudice against religion (which I often share) misses the point. Religion may not be the driving force of history, but economics isn’t either. So what is the driving force of history? The analysis of marxism is flawed and can never lead to the resolution of socialism, an idea that was appropriated by marxists, and turned into a system’s dogma.
Kautsky on Christianity? Are those bozos kidding. Historical materialism is unable to explain Christianity and has instead but marxists on the sidelines of historical analysis.
I recommend a look at the model of history in WHEE: we can see the complexity of the question and the fallacies that arise from materialist reductionism.