Well, since none of us is born good, and none of us overcome our evil nature through great effort, I must say neither. We are all sinful by nature and the only way we can overcome that sinful nature is through Jesus' help.
let me rephrase it with another example, is it better to be born talented and not have to work hard, or born without that talent and work hard everyday to get it.. my personal answer is through effort, because the ones born good or talented are less aware, les dedicated, and will easily slip and fall behind next to someone ready to work hard
Everyone is born good, no one is seriously evil. Evil actions are psychological and only happen if the person doing them honestly believes they are doing the right thing. Even Hitler. I would say that you of course could recover from ANYTHING with good effort, but as long as you turn out happy and fulfilled in life, it doesn't matter what point you start at.