... to keep moving up ... , ...

... to keep moving up ... , you have to abandon the security of that ledge and reach for another hold. Letting go of that sense of security.. is the challenge. ... think of yourself as climbing a ladder. To move to the next rung, you must give up your grip and reach for the next one.
 Nick Vujicic

Quotes from the same author

When you can't get a miracle, you can still be a miracle for someone else.
 Nick Vujicic
Motivation gets you through the day, but inspiration lasts a lifetime.
 Nick Vujicic
... for every disability you have, you are blessed with more than enough abilities to overcome your challenges.
 Nick Vujicic
What kind of husband am I gonna be if I can't even hold my wife's hand? ...but I realized I may not have hands to hold my wife's hand, but when the time comes, I'll be able to hold her heart. I don't need hands to hold her heart.
 Nick Vujicic
I encourage you to accept that you may not be able to see a path right now, but that doesn't mean it's not there.
 Nick Vujicic