Reb Anderson writes in The Third Turning of the Wheel: Wisdom of the Samdhinirmocana Sutra,

A buddha is someone who sees the way things really are. When we see the way things really are, we see that we’re all in this together, that we are all interdependent. A great surpassing love arises from that wisdom, and that love leads a buddha to wish that all beings would open to this wisdom and be free of the misery that arises from ignoring the way things are. Buddhas appear in the world because they want us to have a buddha’s wisdom, so that we will love every single being completely and protect every single being without exception and without limit—just as all the buddhas do.