Shakespeare uses the trials undergone by the lovers throughout A Midsummer Night's Dream to explore different aspects of love.
Hermia believes Lysander's love for her to be more important than her love for her father, or obedience to Theseus, but it is only when that love is removed that she understands its real value. Declarations of love are replaced by words of hatred, leaving Hermia distraught and confused.
The discord between Demetrius and Helena makes their eventual pairing all the sweeter. Demetrius' rejection and loathing are transformed into devoted love by the close of the play.
The most obvious discord is that between Oberon and Titania. At the play's outset they argue violently, and their quarrel sets the remainder of the play's events in action. Their discord has a physical outcome, effecting the weather, the seasons and the natural world.