Partzufim: 2

This combination of the various Sefirot is symbolized by the form of a person (אדם). The Midrash teaches us that the clearest vision seen by the prophets was that of "על הכסא כדמות מראה אדם, On the throne was the form of the appearance of a person." Man incorporates all of the abilities that are found within all the spiritual realms. All of worlds and visions of the chariot are in the spiritual form of Man. It would be impossible to understand the depth of a portion of this form, without an understanding of its entirety.
A person consists of 248 limbs. Imagine if they were all disconnected and piled up. Could someone who has never seen a person figure out exactly how they should be put together, limb by limb? Similarly, without an overarching understanding of the combination of the Sefirot, one will end up with many contradictions as he studies Kabbalistic thought.
This was the main insight of the Ariza"l. He taught the concept of Partzufim, namely that the Sefirot are details in the form of Man which incorporates within it everything of the spiritual conduct of the world. By understanding the greater picture one can then appreciate the depth of each Sefira; what it does as part of the whole. By understanding each Sefira as part of a whole many questions that disturbed earlier Kabbalists are resolved.