Stronger than ungrounded opinion, but weaker than full knowledge. Knowing is considered to entail that p actually is true, while believing p is consistent with the possibility that p is false. People act in accordance with their beliefs. It would be inconsistent to worship God while claiming to believe that there is no God. Not all opinions are equal.
Mere opinions are completely unsupported b.
Reasoned opinions have evidence to support them. There is a popular, but mistaken belief that faith is always unsupported. Furthermore, faith is not necessarily associated with religion. For instance, an employer has faith in their employees. They have a reasonable belief that the car will start and get them to work without breaking down.