Agape

No man takes my life from me; I lay it down by my own choice. [Jesus, John 10:18]

Mature love is sacrificial.  And maturity is a life-long process.  The only love that works in long-term relationships is agape--the Love of Christ.  We start out in life purely selfish.  Infants are, of course, incapable of empathy.  Children don't share their toys easily and want to be the most favored of their siblings.  Adolescents compete for popularity and feel diminished if others are more popular than they.  Young adults enter relationships mindful of what they will get from the relationship. We accept all this as normal.  But we also realize that adults must overcome self-centeredness in order to have successful relationships--successful lives for that matter.  Jesus gave everything He possessed for individuals and for humanity--even His very Life.  And He did not resent it!  He gave freely by His own choice--a fact that He made clear to His disciples, and to all of us. He was not a victim; and He did not allow Himself to feel like a victim because of what He gave.  He is our supreme example in this, as in all aspects of life.
The importance of the sacrificial aspect of love becomes evident when we see that all relationships involve needs-conflicts. It is inevitable that, sooner or later, what I need or desire will be in conflict with what others need or desire. In marriage this is very critical. Sometimes I need to be close while Lynn [my wife] needs some space [or vice versa].   I may want to invite friends over, but she's too tired to be social.  She may want to visit family for a vacation, but I want to go to the beach. In these times, if I get what I need, Lynn doesn't [or vice versa]. A measure of the health of individuals in a relationship is how smoothly or roughly these times are negotiated. If we are unable or unwilling to practice agape/sacrificial love, needs-conflicts will be very troublesome. We can become like two people in a tug-of-war: me and what I need against you and what you need.  If I give in without practicing Christ's Love, I may resent it, and keep score. When two people in a marriage [or any relationship] practice Christ's Love, their relationship becomes more and more harmonious, graceful and peaceful.  Politeness and civility rule the day.  We begin to experience the reality of Ps. 133:1:  Behold, how good and how pleasant [it is] for brethren to dwell together in unity!