Unconditional love is like the love a writer has for their characters. One character might be a villain, or a rude asshole, but they love them anyway, since they enjoy their creation. They are essential pieces in great storytelling.
This is why people usually only experience this unconditional love when they manage to connect to the divine. Because they’re totally not used to it due to lack of exposure, since so few people practice it. But the divine is all about enjoying its creation in its totality. It does nothing but love unconditionally, and that is enough to bring things into existence. It doesn’t play favorites; That’s why anything can happen.
Man says: “Why is this allowed to happen?”
God says: “Why not?”
Man says: “People are suffering.”
God says: “How could it be any other way?”
Man says: “No suffering. Everybody happy.”
God says: “You will get there. Why so impatient?”
Man says: “I don’t want to suffer anymore.”
God says: “Then I cannot allow you to happen.”
Suffering ends when you realize you are one with God. But that can only happen if you accept your separation from God.
Which means loving life unconditionally.
You accept the separation and it allows you to do that, and doing that confirms the unity.