IN PRINTERS' LANGUAGE, to justify means to set type in such a way that all full lines are of equal length and flush both left and right; in other words, to put the printed lines in the right relationship with the page they're printed on and with each other. The religious sense of the word is very close to this. Being justified means being brought into right relation. Paul says simply that being justified means having peace with God (Romans 5:1). He uses the noun justification for the first step in the process of salvation.
During his Pharisee phase, or "blue period," Paul was on his way to Damascus to mop up some Christians, when suddenly he heard the voice of Jesus Christ, whose resurrection he had up till now considered only an ugly rumor. What he might have expected the Voice to say was, "Just you wait." What in effect it did say was, "I want you on my side." Paul never got over it.
As far as Paul was concerned, he was the last man in the world for God to have called this way, but God had, thereby revealing that God was willing to do business with him even if he was in the process of mopping up Christians at the time. Paul also discovered that all the brownie points he had been trying to rack up as a super-Pharisee had been pointless. God did business with you not because of who you were, but because of who God was.
All the Voice seemed to want Paul to do was believe that it meant what it said and do as it asked. Paul did both.
At a moment in his life when he had least reason to expect it, Paul was staggered by the idea that no matter who you are or what you've done, God wants you on God's side. There is nothing you have to do or be. It's on the house. It goes with the territory. God has justified you, lined you up. To feel this somehow in your bones is the first step on the way to being saved.
You don't have to hear a Voice on the road to Damascus to feel it in your bones either. Maybe just noticing that the sun shines every bit as bright and sweet on Jack the Ripper as it does on Little Orphan Annie will do the trick. Maybe just noticing the holy and hallowing givenness of your own life.