The most we know about the nature of particles is given by quantum mechanics. However, quantum mechanics is not about particles. It is about fields or quantum waves. Some people assume that the particles are somehow carried along with the fields. My belief is that only fields exist and that the concept of particles is a useful approximation of what happens when the quantum fields collapse during interaction with other types of foelds- like when EM fields interact with electron fields. Nobody has a theory that describes how this happens. We just know the before and the after, with a black box in the middle.
Presumably the interaction of the sets of fields occurs at Planck times and distances. But that is not really known either. On the other hand, it is only these interactions that are available to our senses and to our instruments. So out interaction with nature is fleeting. We only get information when fields collapse. Penrose claims that that is the basis of consciousness.
So particles have not been proven to exist except in classical physics- more precisely Newtonian physics. However, Newtonian physics has been proven to just be an approximation, (good when large numberes of so-called particles are averaged over), to quantum mechanics. To be more explicit, the solution to Schroedingers equations or Heisenberg's matrix theory yields fields or waves, not particles. There are no particles in quantum mechanics and when they are forced in, they just lead to infinities and fancy mathematics like renormalizations to deal with their presence.
As for my religion, I have practiced almost all of them including atheism, which I consider to be a belief system. I was a christian until college in the fifties, when I decided that the existence of the supernatural did not make sense based on physics. I continued my athesist beliefs thru grad school, getting a PhD in physics and for about 5 years beyond.
Then I had experiences that led me to investigate the paranormal, the occult and eastern religions, and especially theosophy, which gave me mechanistic processes by which the supernatural worked- just like physics. Then also science was changing towards the possibility of the existence of a supernatural, as it continues to do so today.
I was married to a jewish lady at that time, so I converted to Judiaism, with an emphasis on its mystical traditions, and retained my interest in eastern religions. Eventually my whole family migrated into Hinduism, and I even lived in a Hindu ashram in the state of NewYork for 6 months teaching math and physics to the children there, before getting kicked out. Right now I have developed my own personal religious practice that combines elements of all religions. From the perspective of a former atheist, all religions are true in essence, although inconsistent in detail, or the basic premise of all religions is false. So I cannot choose one over the other, including atheism.