If it was compulsory to join a religion I would have to make up my own.
Religion ultimately depends on three primary things: ignorance, faith and reward. What useful thing can you do with mainly irrational ingredients?
There is no merit in denying scientifically determined facts but you have to do so if your purpose is to be a "believer". Faith is involved because the beliefs are based on the words of invisible creatures who are spelling out the holy imperatives. Religion only works if the believer is promised a reward otherwise why put yourself through foolish hoops if there is no benefit at the end?
Now my cat has been seen by neighbours leaping six feet off the ground and catching pigeons in mid-air which he drags home alive through the cat flap and devours in the kitchen shedding sacrificial blood with feathers all over the place. He is ignorant of human things although it has to be said he is highly informed and expert in rodent and bird demolition. Despite snacking all day long on these creatures he still has faith in the reward of me feeding him, so in the absence of anything better I will have to go for the Cat Feeding Religion. Like the irrationality found in all "True Religions" it is mad that I feed my cat when he is perfectly capable of looking after himself.