Prayer involves transformed passions. In prayer, real prayer, we begin to think God's thoughts after Him: to desire the things He desires, to love the things He loves, to will the things He wills.
No matter how much care we put into hiding our passions under the appearances of devotion and honor, they can always be seen to peer out through these covers.
Sloth is all passions the most powerful.
Of all the violent passions, the one that becomes a woman best is love.