This is a great truth, and one which, it must be admitted, is difficult to be realized by those who have not an instinct of perception and of affirmation in their own purified hearts. Those who are the subjects of this exalted feeling sincerely desire the happiness of all those, whoever or whatever they may be, who are capable of enjoying happiness while, at the same time, it may be so, that they disapprove and perhaps even hate their character; and, accordingly, they love the evil as well as the good, sinners as well as saints.
We have a striking illustration of the nature of pure love in the case of the Savior. He loved sinners. "He came not to call the righteous, but sinners to repentance." It was not for angels, but for erring men, that he died. He bowed his head upon the cross for those that persecuted him, reviled him, slew him. He loved men, not because they were good, for such they were not, and certainly not because they were evil, because evil can never be the foundation of love, but because they were existences, — percipient and moral existences. He saw them created with the elements of an eternal being, but destitute, in their fallen state, of those attributes which would make that being a happy one. He saw them destitute of truth which they might possess, of holiness to which they were strangers, the enemies of God when they might be his friends, the heirs of hell when they might be the heirs of heaven. He loved them, therefore, not because they were good, but because they had a sentient, and especially because they had a moral, existence. It was their existence and not their merit; it was what they were capable of being, and not what they were, which brought him down from heaven.
—edited and adapted from A Treatise on Divine Union (1851) Part 4, Chapter 1.