Christians, what is your absolutely favorite affirmation from the Bible?

Mine is from Romans 8:28, and it constantly reminds me that everything that happens to me will work out for my good in the end. I might not enjoy it at the time, but someday I will be able to look back and say, "God allowed that to work out for my benefit after all!" So, as a Christian, what is your favorite affirmation or encouraging scripture/thought from the Bible? I can't wait to read these!