Is love emotional or rational?

There is commonly accepted belief that love is based out of sentiments. Well love is not entirely based on emotions. It seems there is rational aspect to it too. Probably that's why one expresses more or less love depending upon the behavior of  the person he loves. It is true for any relation be it couple, parents and children or brother and sister. In any family, the most obedient child gets more love than other children from parents.   In case of a couple, if one is not very caring then the love of the other person also tends to reflect the same.  It also holds true in the relationship of brother and sister.

This is true even in the relation of worshiper and God. In case he gets joys and happiness from God, his love strengthens. But the moment he gets sorrows, his love and devotion for God starts decreasing. Had the love been emotional, it should have been the same throughout in any relationship.