Shakespeare
Sonnet 116
The Picture of True Love

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 wand'ring 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.

"Greater love has no one than this, that He lay down his life for His friends." John 15:13

"I have been crucified with Christ and I no longer live, but Christ lives in me. The life I live in the body, I live by faith in the Son of God, who loved me and gave himself for me." Galatians 2:20

"Love is not the world, neither the things that are in the world." 1 John 2:15

"Husbands, love your wives just as Christ loved the church and gave himself up for her." Ephesians 5:25

"Very rarely will anyone die for a righteous man, though for a good man someone might possibly dare to die. But God demonstrates his own love for us in this: while we were still sinners, Christ died for us." Romans 5:7-8

"Whoever does not love does not know God, because God is love...This is love: not that we loved God, but that He loved us and sent his Son as an atoning sacrifice for our sins." 1 John 4:8,10

"The Lord disciplines those he loves, and he punishes everyone he accepts as a son." Hebrews 12:6

"There is no fear in love. But perfect love drives out fear, because fear has to do with punishment. The one who fears is not made perfect in love. We love because he first loved us." 1 John 4:18-19

"Who shall separate us from the love of Christ? Shall trouble or hardship or persecution or famine or nakedness or danger or sword?...No, in all these things we are more than conquerors through him who loved us. For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord." Romans 8:35, 37-39

"This is how we know what love is: Jesus Christ laid down his life for us." 1 John:3:16

Shakespeare was right - true love is everlasting and selfless.