Ok, Let’s start with the concept of paradox. The prefix para means “alongside.” The root word here comes from the Greek dokeo, which means “to seem, to think, or to appear.” A paradox, then, is something that seems contradictory when we first encounter it; however, with further scrutiny, the tension is resolved. That's been my experience with the Trinity.
For others the real tension may occur when encountering mysteries and contradictions. We use the term mystery to refer to things we do not yet understand. We may believe a mystery is true, but we do not understand why it is true. For instance, we know that there is such a thing as gravity, but the essence of gravity remains something of a mystery to us. Even something as basic as motion, which we notice and utilize every day, defies an acute analysis. When we look at it philosophically, we have to say that there is a mysterious element to motion, and the same is true for many other things that we experience in our everyday lives.