Proselytism /(?)/

Pros·e·ly·tism

Proselytism

n.
  1. The act or practice of proselyting; the making of converts to a religion or a religious sect, or to any opinion, system, or party.
    They were possessed of a spirit of proselytism in the most fanatical degree.
  2. Conversion to a religion, system, or party.