That's because human behavior and rifle bullets are not similar phenomena. Rifle bullets are inanimate objects whose motions are constrained by the laws of physics. Human behavior is not a physical thing at all, but is the result of the electrochemical workings of the brain. It is just very difficult to know which they are. On the same basis we believe in other phenomenon of which we do not have perfect knowledge.
Religion deals with emotion while science deals with reality.
No, religion deals with spiritual reality, while science deals with physical reality. Physical reality can be shown to exist. Therefore, what's being said here is that science deals with what exists and religion deals with what doesn't. It is not logic, nor is it support for the existence of God. And of course, neither does it support arguments He doesn't exist.