Your words are not from the lyrics, but from the famous American civil rights leader Martin Luther King. The original sentence is:

If you can't fly, run; If you can't run, then go; If you can't walk, climb, but whatever you do, you have to keep moving.

Chinese means:

If you can't fly, run; If you can't run, then go; If you really can't walk, climb. No matter what you do, you should go forward bravely.