St. Gregory the Great:

“‘And my Father will love him, and we will come to him and make our home with him’ (John 14:23). My friends, consider the greatness of this solemn feast that commemorates God’s coming as a guest into our hearts! If some wealthy, influential friend was coming to your house, you would quickly put everything in order for fear something there might offend your friend’s eyes when he entered. Let all of us then who are preparing our inner dwellings for God cleanse them of anything our wrongdoing has brought into them.”