I don’t personally know that MLK had this specific quality. I've made explicit what you have implied, that he did. Even if he did have it, I don't think you could reduce his general capacity for love to this one idea, hence "part of." But to avoid apparent arrogance, perhaps the first sentence of the second-to-last paragraph might be written like so.

"This perspective I’m developing is part of what gave Martin Luther King the capacity to feel universal love and compassion."