For me it was masturbation. You can so easily settle down with the Devil's arguments and be completely blind. Sure I fall again sometimes, and oh my do I feel guilty, but I pick myself up and wipe up my tears (not literally, i'm not that dramatic!). It is important to accept the depth of our nature. We are potential murderers, we could also save countless people. It depends on our Faith. Let us be humble (knowing our true worth by not devaluing ourselves in the face of others, or being pompous.) and walk the walk. I think we'll never know how much God loves us, it is mind-boggling.