Jessica Ahlquist's talk from the Secular Student Alliance annual conference is online. I can confidently say it was my favorite talk of the whole conference - and that's competing with excellent talks by Greta Christina, PZ Myers, Jamila Bey, and David Silverman.
In other words, I order you to watch the whole thing right now. You won't be disappointed.
I wish I had been as strong as Jessica when I was a sophomore in high school.