Is pre-Qin Confucianism a religious belief system?

No. Confucianism is basically an academic system. This is a philosophy about real life. At first glance, Confucianism is very similar to religion, but a little deeper understanding of Confucianism will reveal that Confucianism has obviously joined the WTO and opposes personality worship. Confucianism worships gentlemen, that is, people who can show the essence of human beings to the greatest extent. As some scholars have pointed out, under the western cultural background and context, Confucianism can be understood as the religion of China people in some form (such as idolatry, mode of communication, extensive influence, etc.). However, under the cultural background of China people, when we fully analyze its essence, we should firmly believe that Confucianism is a school and an outstanding school, not a religion.