General:
* Trust: This implies confidence and reliance.
* Have faith in: Similar to trust, this suggests a strong belief in something's reliability or integrity.
* Accept: This suggests acknowledging the truth or validity of something.
* Be convinced of: This implies a strong belief based on evidence or reason.
* Be persuaded of: Similar to "be convinced of," but often implies influence from someone else.
* Hold to: This signifies a strong and unwavering belief.
Specific to religion:
* Have faith in: This is often used to describe belief in a higher power or a specific religious doctrine.
* Be devout in: This suggests deep religious commitment and practice.
* Be a believer in: This indicates adherence to a particular religious tradition or ideology.
Other possibilities:
* Count on: This emphasizes reliance and expectation.
* Be sure of: This suggests certainty and conviction.
* Be confident in: This emphasizes a strong sense of assurance.
The best synonym depends on the specific context and the nuance you want to convey.