Yesterday in our discussion group, we talked about the different shades of the Left and its origins.
From my perspective—as an atheist from a family of atheistic or very secular farmers—the leftist approach actually stemmed from village life, which demanded cooperation.
In order to purchase land, they came together as a farming cooperative. This wasn't 'Communism' as a state economy or a rigid ideology; it started as something purely practical. A tractor is extremely expensive, and you need several different types throughout the growing season. If the village is organized economically, they can share these costly tools.
Furthermore, by organizing, they could trade and sell more effectively, utilizing their collective purchasing and selling power to better navigate a capitalist society and a free market