"...all solid relationships are built on quid pro quo: doing something for someone who, in turn, does something for you."
In reading a business article this morning, I came across the above sentence. It indicates that relationships are give & take; that, you serve someone because you know they will serve you back. This view indicates that love and service to others is motivated by their love or service back to you.
While the above has some practical value in business relationships, it is not the principle of Christian relationships. Love takes joy solely in loving others; not for some favor that may be returned. To modify the above sentence...
"...all solid relationships are built on love: rejoicing in doing something for someone who, in turn, may or may not do something for you."
Ultimately, God is the perfect lover, and true love follows his example. "In this is love, not that we have loved God, but that he loved us and sent his Son to be the propitiation for our sins" (1 John 4:10). God's love was initiated not based on our love or service to him. Neither should our love for others be.