In the third person

 

Or perhaps it´s the Knower (Father), the Known (Son) and the Knowing (Holy Ghost). Although it´s possible that a dyad might do the trick, as well. See Shiva-Shakti, Krishna-Radha, and so forth.

To be perfect, God must know Himself. And to be perfectly loving, He must love Himself as Another. 

Or Herself, if that´s more your thing.