This is a pretty great song.
It’s essentially about how the lead singer found wholeness with his wife. She’s the “tear in my heart” sounds bad, but what he means is “my heart is my armor, she’s the tear in my heart, she’s a carver, she’s a butcher with a smile.” I think he means this in sense that whatever reservations he has about personal growth or the kind of vulnerability it takes to do courageous things are are aspects of his life that his wife helped him find. Good marriages are like this. You have a helper.