Soli Religion

The Solis made religion and the priesthood illegal hundreds of years ago after a disaster within their planet. A religious cult, arguing that science would be the death and end of the Soli people, attacked a research lab, killing all the scientists and destroying valuable scientific resources.
  Most Solis by that point in history had abandoned religion, embracing science and ethical philosophy as a guide for daily inspiration and decision-making. A few still practiced older religions, but they were few and far in-between, mostly practicing alone or within their pods. However, the rise of the cults met a need for some Solis to feel connected to a greater power. The Soli political entities became concerned with the rise of the cults, but did not one to clamp down on freedoms of their people. This held, until the attack on the lab. They worried that other cults had similar plans.
Ultimately, the Soli government decided that the current evolution of their society left no room for religion. They outlawed religious practice. Many Soli initially objected to this, even though they didn’t practice religion. They wanted the freedom to practice, if they chose, even if they didn’t take advantage of it. The Soli government debated the terms of the outlaw for months, dealing with citizen protests and internal strife. Several religious leaders and their followers petitioned the capital, calling for the separation of their movement from those of the cults.
Ultimately, the Solis decided to keep the practice of religion legal but banned any sort of religious organization or structure. There could be no priesthood or formal leaders of any religion, rather gatherings must be organic from citizens with rotating or undefined leadership. People must register their religious affiliation and be open to government inspections of gathering and occasional individual questioning on belief systems.