Love is not a feeling
There is the feeling of love, and then there is the decision of love. The feeling of love comes and goes — it ebbs and flows like the waves of the ocean (just like all the other emotions).
But the decision of love is controllable. It means choosing to love. It means loving despite the circumstances. It means loving despite not always wanting to. It means sacrifice.
The feeling of love does not last. It is the decision of love that stands the test of time and endures all things. It is this kind of love that we should seek. And it is this kind of love that we must give.