You are enough.

This is what I would say to my child, if he or she felt desperately alone or unwanted:

(I have four children; undoubtedly at least one will inherit my fear of falling short.)

You are good enough, just the way you are. You are enough.
If you never progress in any area for the rest of your life, I still love having you in my life.
Even if you believe you are failing harder than ever, you’re not.
(But even if you were, I wouldn’t care.)
I can’t imagine loving anyone as much as I love you.
I wouldn’t trade you for anyone else in the world.
Even if you feel like all you are is “a thousand problems,” I take them in a heartbeat, because I am crazy about you.
Don’t turn away from the ones who love you most, believing you’ll never be enough for them.
I expect nothing from you. The things I try to teach you- they are just lessons. Not expectations.
You might think everyone would be happier without you. That’s an absolute lie.
I would be devastated to lose you. I’m not sure I would recover.
You, with your quirks and failures and flaws, and all your fears- you are perfect just the way you are.
There’s nothing to “measure up” to- the standard is nonexistent; you “measured up” the moment you were born, and you’ve never fallen short since then.
You are perfect just the way you are, and I love you more than you know. 

Hmmmm. I believe I will start telling them these things now.
Who wouldn’t want to hear, you are perfect the way you are?