Grace for grace is an updated version of "eye for an eye," or a "tooth for a tooth." Exodus 21:24 Think of equal measure.
John the Baptist, in talking about Jesus was saying:
He who comes after me ranks before me, for he was before me. And from his fulness have we all received, grace upon grace. For the law was given through Moses (see first paragraph), grace and truth come through Jesus Christ. John 1:15-17.
In following Christ, our aim is to be like Him. His behavior becomes ours, in particular His relationship to His Father. In graced living Christ becomes the doer of our actions. In imitating Jesus, we are filled with grace, and in loving like Jesus, we pass on grace. We live as Jesus would.