Diary of St. Faustina, 1682
+ May 1, . This evening, Jesus said to me, My daughter, do you need anything? I answered, "O my Love, when I have You I have everything." And the Lord answered, If souls would put themselves completely in My care, I Myself would undertake the task of sanctifying them, and I would lavish even greater graces on them. There are souls who thwart My efforts, but I have not given up on them; as often as they turn to Me, I hurry to their aid, shielding them with My mercy, and I give them the first place in My compassionate Heart.
It seems rather counter-intuitive. You love someone, so that means that you must abandon them completely to another. That sounds like exactly what you shouldn't be doing. However, that all changes when you see how much the other can take care of your beloved. Take for example a child who gets cancer-a very painful cancer like pancreas, bone or lung cancer. The child is in constant pain. There is throbbing burning pain even while resting that leaves the child crying day and night. The child will die in a matter of months. Of course the mother can't do anything about it. She has no pain relievers powerful enough. She has no way to treat, much less cure, cancer. She can't do anything to relieve the pain, let alone prevent her child from dying this horrible death. All she can do is abandon her child to a doctor who is able to treat the disease and make it more bearable, while giving the child a chance at surviving.
This is what we must do with sinners. If someone we love has been butchered by a life of sin, we must hand the person over completely to the Divine Physician. God can give us a better life than we can give ourselves, just because He's God, so we must let Him decide how things will turn out, so that the result might be greater. Therefore, the more we abandon those we love to the care of God, the more we are leaving God free to improve them as He wishes. Otherwise, we are limiting God inside of the life we are trying to compose for the beloved. If God is free to compose the beloved's life, the that person's life will be greater. When you love someone, you want them to have the greatest life possible. Sometimes that means abandoning them completely to someone more powerful than yourself, like the mother abandoning her sick child to a doctor. So if we want someone to be a good person, we must abandon them completely to God, leaving Him alone to decide the outcome, that the one we love might have a better life. It is these sorts of sacrifices that show our love for others, not words or happy times together.