The biblical references doesn't mean this song is about God. This song, to me, is about the feeling of when you are best-friends with a girl/boy and you love them (aka the "friendzone") and want to be with them but the feeling's not reciprocated. You are just someone who makes their life better by helping them to see things clearer about what they want (when Jesus puts the mud in the man's eyes and he can see) but you want to be more than just that. You want to be the person they want. You want to be the perfect partner for them, their ideal partner and you're willing to change to be that person (the clay in the hands, the bible verse where God is the potter and man is the clay) by doing everything you can and they want you to do, to be that person.