Hashem dwells in each and every person who prepares themselves to be worthy of housing Him. How can one be worthy? Through acting properly to his fellow man. The Kohen Gadol (high priest) demonstrates this through the Urim Vetumim of the Choshen Mishpat (breastplate of Judgement) which he wore on his heart. The Choshen (breastplate), with its twelve stones, would resolve conflicts between people so we will be one unified nation and Hashem can rest on us.