There is no safe investment. To love at all is to be vulnerable. Love anything, and your heart will certainly be wrung & possibly broken. If you want to make sure of keep it intact, you must give your heart to no one, not even to an animal. Wrap it carefully round with hobbies & little luxuries; avoid all entanglements; lock it up safe in the casket or coffin of your selfishness. But in that casket—safe, dark, motionless, airless--it will change. It will not be broken; it will become unbreakable, impenetrable, irredeemable. The alternative to tragedy or at least the risk of tragedy, is damnation.
From "The Four Loves" by Clive Staples Lewis
Here is a good article from the Gospel Coalition.
Here is the quote illustrated from Zen Pencils.