So as we wish to understand those things which are above our formal object, we need to remember two things. First, whatever we understand is going to be in terms of the natures of bodies, and secondly, we are going to have to employ analogy to take this step. Yet there is something in common. Well, angels and men have in common that they are both beings, but are very different in the type of beings they are. Angels are pure spirits.
Men are spiritual and corporeal.
Angels are immortal. Men are mortal. Angels understand without reasoning. Men reason in order to understand. There are many differences.