The Bishop showed Christ to him. "I was a stranger and you took me in." He forgave the theft of his valuables, and made a gift of it, telling him by his actions, "Go, and sin no more."
Jean had a struggle with his soul after that encounter, as we all do. Accept Christ and His mercy and forgiveness, and follow Him by showing His love to others? Or continue in our sin, go on hating our enemies and seeking revenge, grabbing what we can, stepping on anyone who gets in our way?
He tried by his own strength to live up to the Bishop's standard, but failed miserably when he encountered a boy who lost a coin. Stepping on it, Jean refused to let the child have it, threatening him until the boy ran away. Immediately, he was plunged into deepest despair, bitter conviction, acknowledgment that he was a sinner in need of the Savior.
It's not an easy decision, and it must be made daily. There are many temptations along the way. Jean became a wealthy man, a leader in his community. A woman was fired from his factory; he could ignore her and send her away, or choose to seek medical care for her, be with her in her last moments, care for her child after her death.
Jean Valjean, a man of wealth and power, got down on his knees in the mud to rescue a workman pinned under a heavy cart, knowing that this action would lead to suspicions from his old enemy, Inspector Javert.
Later, when Javert's suspicions were allayed by the arrest of another man thought to be Valjean, it would have been so easy to let the mistake stand. To let another man be imprisoned for life in his stead. Another struggle with his conscience, with God. In the end, he chose to do the hard thing, the right thing. He came forward and revealed his true identity, bringing himself (now no longer a young man) and the young Cosette back to a life of running and hiding.
Valjean later aligns himself with a revolution against the French government. Inspector Javert, now a spy of the government who has infiltrated the protesters' headquarters, has been discovered and is tied up awaiting death at their hands. Valjean agrees to do it, but instead frees Javert, his old enemy who had devoted his life to his pursuit and ruin. Javert, conflicted by his devotion to law and duty and his debt to Valjean, a criminal, threw himself off a bridge. He could not reconcile justice and mercy.
This is the contrast between the two: Javert is stern, unforgiving, a symbol of righteousness and justice, law and order. He knows no mercy, no compassion. The law must not be waived for anyone, for any reason. Valjean, who is shown forgiveness and grace, comes to exemplify mercy, compassion, and unselfish love.