Free Will: The ability of an agent to make genuine choices that stem from the self. Libertarians argue that free will includes the power to determine the will itself, so that a person with free will can will more than one thing. Compatibilists typically view free will as the power to act in accordance with one's own will rather than being constrained by some external cause, allowing that the will itself may ultimately be causally determined by something beyond the self. Hard determinists deny the existence of free will altogether. Most Christian theologians agree that humans possess free will in some sense but disagree about what kind of freedom is necessary. The possession of free will does not entail an ability not to sin, since human freedom is shaped and limited by human character. Thus a human person may be free to choose among possibilities in some situations but still be unable to avoid all sinI'm not sure how Libertarian Free Will applies if it does not entail the ability not to sin. I agree it doesn't and I do not deny that humans possess personal will but I wouldn't call it Free Will as Brian defines it here. I think the definition covers what people mean when they use the term "Free Will", but I don't think we have it because without Christ we do not have the ability not to sin. Notice that I am not saying that people can't choose to do good things. I'm saying that without Christ we lack the ability to never sin in word or deed. Life become choosing which sins we indulge in and which ones we avoid with no hope of ever pleasing God. If we truly had Libertarian free will, we should be able to decide to not sin and Jesus' sacrifice would not have been needed to save His people.
Apologetics 315: Terminology Tuesday: Free Will