Why is it important to maintain a couple's love?

Do you know why it is important to maintain the love of a couple?

Some important tips to maintain the love of a couple:

there must be respect.
understanding one with the other.
bring a good dialogue (communication).
there must be tolerance.
that romance is at all times.
accept each other as they are.
that you feel complete with your partner.
help each other in everything.
always be in the most difficult moments of life.
be faithful to your partner.