What is love

Two person are in love with each other with all their heart. They made each other happy, they made each other sad, they hurted each other, but they were always forgive each other. They are love. They love each other flaws, because yes nobody in this world perfect. Above all, all we need is God's hand writing or destiny, we can't force universe, if someone is belong in our life, it will, no matter how long and how far it takes. Both of them think that they are not meant to be to each other, they think they are meant to be to somebody else.
What kind of love is that? is it true?

What if they're both wrong?

or maybe,

they are right.

only heaven knows.