Sometimes it is tough. We are fickle creatures at the best of times. It is easier to express our love and appreciation for the Lord when things are going well, or at least there are no negative or bad situations around us or within us.
"Be not afraid to tell Jesus that you love Him; even though it be without feeling, this is the way to oblige Him to help you, and carry you like a little child too feeble to walk." St. Therese of Lisieux Thoughts of St. Therese pg. 114
When things are indeed rough, or very painful, it can be difficult to think of offering our love to the Lord then. How can we offer love in the midst of such suffering?
It is amazing that St. Therese makes this statement as she was living with the constant pain of illness. Especially towards the end of her life.
Jesus, I love You! Jesus, I love you! Jesus I love You!