First I sinned

A man once approached Rabbi Israel of Rizhin:  "Rabbi," he said, "I so wish to repent, but I don't know what to do."

The rabbi replied:  "And to sin, you knew what to do?"

"Yes, but that was easy.  First I sinned, then I knew." 

"Exactly," responded the Rabbi.  "Now do the same the other way around.  Start by repenting; you'll know later."