What if any, is the difference between knowing something and believing something? This itself is a massive philosophical question and I only here want to reflect in general terms about one way in which we use such language in general conversation. 
Consider general conversation. We may ask someone what they believe about a topic or an issue—perhaps God or climate change—and we may even ask them why they believe so, but we do not generally ask people what they know about such things. Why is this? When we use the language of belief in such a situation we are implicitly acknowledging a plurality of perspectives on the issue. To ask someone what they know about God would be to suggest that one wants to take on board what they say as fact. For example, it is typical to ask professionals and experts for their knowledge in an area, but we may even ask experts what they believe if we think we might currently hold a different position.
From the other side of the conversation it would be out-of-place to answer a question about ones beliefs by stating what one knows; this can create discomfort because knowledge carries with it a universal claim. We speak about knowledge in the areas of science for example, of matters which we can access through our senses and which we can reach assured results. Belief however does not hold a universal claim. We often use the language when referring to matters which are beyond the reach of our senses, for matters which we cannot reach assured conclusions on. Such things are often placed in the category of personal preference because we cannot truly know the facts.
So the language of belief in general conversation allows for a diversity of perspectives and stops short of making a universal or factual claim upon others. The language of knowledge on the other hand does make universal claims and we do not use it when asking people about controversial matters.
But in using the language of belief are we are in risk of inadvertently nodding our head to two features of contemporary culture: pluralism and uncertainty. In common conversation about God or religion the language of belief can make way for the acknowledgement of a plurality of perspectives, and this is helpful. But if we are not careful our partners in conversation may get the impression that we consider our positions to be beliefs because they fall short of an adequate basis that makes for knowledge. We do not want people to get the idea that we only believe but do not claim to know, either because we lack certainty or reasonable and intelligent grounds for them, that there is no way of us truly knowing, or that they reflect mere personal preference as that which suites us.
Assuming you don’t fall into any of these categories, this is a bad impression we need to avoid! So lets be consious of the language which we use when we speak with others.
 I am not addressing how such language may function in the Bible, theology, or academic discourse, only in general/common/informal/everyday conversation.
 Consider a television or radio interview. If the interviewer intends to present the interviewee as an authority on the topic to enlighten the audience, then they will often frame the questions in terms of knowledge rather than belief.
 This is simply how the language is often used, regardless of the inadequacies of the epistemological assumptions that under gird it.