Aaron must bring forward his sin-offering bull and atone for himself and for his household [i.e., his wife].
In order for the Yom Kippur rites in the Sanctuary to be valid, the high priest needed to be married, and return directly home to his wife after completing the Yom Kippur rites.
The purpose of his attaining high levels of Divine consciousness in the Holy of Holies is in order to apply this inspiration to everyday life. Since women personify our drive to make the world into G-d's home, the high priest's return home to his wife -- sharing his Divine inspiration with her, thereby enabling her to develop and expand her own Divine consciousness -- is the culmination of the intense spiritual work of the day.
The Yom Kippur rites instruct us how to renew our relationship with G-d. Thus, fostering our own marital harmony is an integral part of fostering our relationship with G-d. Husbands must encourage their wives' spiritual development. And we must all strive to harmonize our "male" sides, i.e., our aspiration to spirituality, with our "female" sides, i.e., our aspiration to bring spirituality into our daily lives.