How many times have you told yourself, "I'm not good enough," or "I'm not skinny enough," or "I'm not smart enough." Whatever "it is," it's the devil talking to you...and to me, trying to defeat us. God tells us in Psalm 139:14 that "I praise you because I am fearfully and wonderfully made; your works are wonderful, I know that full well." Meditate on this part: "I am ...wonderfully made." Try repeating it over and over when you are thinking negative thoughts about yourself. If that is not enough, what about this verse from Genesis 1:26: "Then God said, 'Let us make man in our image, after our likeness." Yes, we are made in the likeness, the image, of God. I have trouble with this one at times, but since He said it, it is true. God does not lie.
American culture, in particular, has labelled women who are not size 0 as nothings, less than worthy of any consideration for anything. All we need do is look at the fashion magazines at the check-out line for confirmation. THEY are the ones who are lying. The world's idea of beauty and worth are distorted in Hollywood and the fashion industry. We are not to look to them for our self-worth, for we are to be set apart from them. While we are "in" this world, we are not "of" this world. We get our worth from God, not the culture.
When you start to doubt yourself, your looks, or your abilities, remember who made you. Commit Psalm 139: 13-14 to memory: "It was you who created my inward parts; You knit me together in my mother's womb. I am fearfully and wonderfully made" by the creator of the universe itself. Let that sink in. God knew us in our mothers' wombs. He made us the way we are. Whether we are tall, short, or average, He knew that before we were formed in the womb. He knew our hair, be it curly or straight. He knew our skin tone, be it pale, dark, or in between.
So, when that nasty voice in your head starts to berate you for whatever reason, push it down. Don't listen. You ARE good enough!