Webster's College Dictionary
Belief:
1. Something believed; opinion; conviction.
2. Confidence in the truth or existence of something not immediately susceptible to rigorous proof.
3. Confidence; faith; trust.
Religion:
1. A set of beliefs concerning the cause, nature and purpose of the universe, esp. when considered as the creation of a superhuman agency or agencies, usually involving devotional and ritual observances, and often containing a moral code for the conduct of human affairs.
Proselytize:
1. To induce someone to convert to one's own religious faith.
2. To induce someone to join one's own political party or to espouse one's doctrine.
Neither beliefs or religion include proselytizing within their definitions. Debates or discussions about religions and belief systems are just that - opinions shared, based on internal convictions.