The plural of belief is beliefs.
When we take a noun like ‘belief’ and want to refer to more than one, we typically add an ‘s’ at the end to form the plural. This follows a common rule in English where most nouns simply require the addition of ‘s’ to become plural. For example, ‘dog’ becomes ‘dogs’, and ‘car’ becomes ‘cars’. In the case of ‘belief’, the same transformation occurs, making it ‘beliefs’. This plural form is used when discussing multiple convictions, thoughts, or opinions held by individuals or groups.