What is the difference between justification and sanctification? Christians use the terms justification and sanctification a lot, but it's not always clear where one concept leaves off and the other picks up.

What do Protestants generally say is the difference between these two ideas? What is the Biblical justification* for having two distinct terms?

* Sorry, I couldn't help myself
Justification - being declared perfect, a single act of Grace by God to the repentant sinner
Sanctification - the process of being made perfect, a day by day activity of God and the Christian working in partnership
Glorification - becoming perfect, the moment when the struggle is over, heaven is entered and God completes his masterpiece: You.

Relevant Biblical verse:

Hebrews 12:2 emphasis mine
Let us fix our eyes on Jesus, the author and perfecter of our faith, who for the joy set before him endured the cross, scorning its shame, and sat down at the right hand of the throne of God.


author means He started and continued it
perfecter means He finished it