"The true mind can weather all lies and illusions without being lost. The true heart can touch the poison of hatred without being harmed. From beginningless time, darkness thrives in the void, but always yields to purifying light. In the era before the Avatar, we bent not the elements, but the energy within ourselves. To bend another's energy your own spirit must be unbendable, or you will be corrupted and destroyed."
- Said by the Lion Turtle
My favorite part is:
"The true mind can weather all lies and illusions without being lost. The true heart can touch the poison of hatred without being harmed."
Overall, I find much wisdom in all the Lion Turtle said to Aang.