I find your point of view reasonable, inasmuch as you believe that Jesus left us with a precise set of beliefs that we must adhere to.
However, Jesus did not leave us this set of beliefs. What He said was, “Whoever listens to you , listens to me” and “I am with you until the end of time.”
Catholics do not have a set of beliefs. Here is our act of faith :
Act of Faith
O my God, I firmly believe that thou art one God in three Divine Persons, Father, Son, and Holy Ghost; I believe that thy Son became man, and died for our sins, and that He will come to judge the living and the dead. I believe these and all the truths the Holy Catholic Church teaches because Thou hast revealed them, who canst neither deceived nor be deceived.
What the Catholic Church teaches does not change, but it evolves in the sense that it becomes explicit or is derived from other revealed truths.
The Church is the living Christ, teaching us every day.