William Shakespeare sonnet 116

Let me not to the marriage of true minds
Admit impediments. Love is not love
Which alters when it alteration finds,
Or bends with the remover to remove:
O no; it is an ever-fixed mark, 
That looks on tempests, and is never shaken;
It is the star to every wandering bark,
Whose worth's unknown, although his height be taken.
Love's not Time's fool, though rosy lips and cheeks 
Within his bending sickle's compass come; 
Love alters not with his brief hours and weeks, 
But bears it out even to the edge of doom.
   If this be error and upon me proved,
   I never writ, nor no man ever loved. 


I thought of this right away because it shows how amazing love is and how strong it is. "to my Dear Husband and loving Husband" and "Sonnet 116" both talk about how they cannot explain how strong love is or hoe you just don't stop loving someone.