Can you explain to me why Confucianism never became a religion as Hinduism or Buddhism did?
For the same reason that Mark Twain never became a religion: they both had clever, witty sayings, many of which can help improve your life. But Confucius wasn't promoting a path to God/diety. Religion, by definition, is a prescribed path to a higher power. Confucius was about living life here on earth and interacting with one's fellow humans; not about how to live life in order to prepare for the next life.
Purpose of Human Existence?
The way I see it, all physical matter has a tendency to, what I call, be "happy," or stabilize. An example of what I mean is certain molecules lose or gain electrons in order to "stabilize." Well humans may be just a coincidence of particles forming into what we are. And as humans, we try to do what makes us "happy," or stable, in a sense. So there is no real purpose for us in this universe, but rather we are just following the laws of the universe. But this is just an opinion from an atheist, and new to the subject, I'm interested in what other opinions are, religious or not.
What is the purpose of life?
You are a smart man. Most of us ponder that question at some time in our lives. But the word "meaning" in that inquisition isn't a practical word to use in the phrase. "Purpose" of life would make it a much more meaningful and comprehendible question. Which would cause me to seek the truth in a much more 'meaningful" and practical way. I do believe that the psalms, proverbs, and the "SONG OF SOLOMON", is the best place for you to find what you are seeking. You shall discover that King Sol. always began by speaking of purpose, therefore disclosing the fact that God answered his personal prayers because he was sincere about what he asked for. Still I strongly suggest that you never pray for wisdom, because the path of enlightenment can be a long and winding road. I will share some things with you that I know. We as human beings, are like plants that grow from the earth, or like limbs that grow from a tree, or like fruit that grows from the limbs of the trees, speaking in biological terms, the quasiquantum explanation of our physical life on this planet is much more complicated, yet much more simple, than any scientist can begin to understand. DNA is created from spiritual resonance, which causes proteins to come togather in an embedded process, (remember form follows function) that is capable of regeneration, it is sort of like a microscopic, bio-LOGICAL computer/antenna/self-regenerating circuit in which a spirit is able to live and function for the duration of a learning process. The soul is part of that process also, which is the ability to percieve and apply emotion and it is created in the mind by the spirit through the valence function of fractal element chemical frequencies. If you would like to discuss this further or have any other questions feel free to contact me at starcrosse2012@yahoo.