" It is impossible to make sense of the doctrine of original sin if we ignore this principle of Adam's headship. Ultimately, it is impossible to make sense of Scripture at all without understanding this vital principle. In an absolutely crucial sense, even the truth of the gospel hinges on this very same idea of representative headship. Scripture says that Adam's headship over the human race is an exact parallel of Christ's headship over the redeemed race. In the same way that Adam brought guilt on us as our representative, Christ took away that guilt for His people by becoming their head and representative. He stood as their proxy before the bar of divine justice and paid the price of their guilt before God. Jesus also did everything Adam failed to do , rendering obedience to God on behalf of His people. Therefore, 'by one Man's obedience many will be made righteous'. In other words, Christ's righteousness counts as ours, because He took His place as the representative Head of all who trust Him. That is the gospel in a nutshell.
Don't get the idea, however, that Eve's sin was excusable because it wasn't as deliberate or far-reaching as Adam's. Eve's sin was exceedingly sinful, and her actions demonstrated that she was a full and willing partner with Adam in his disobedience. Incidentally, in a similiar way, we all demonstrate by our own willful deeds that the doctrine of original sin is perfectly just and reasonable. No one can legitimately cast off the guilt of the human race by protesting that it is unfair for the rest of us to be tainted with guilt for Adam's behavior. Our own sins prove our complicity with him. "
― John F. MacArthur Jr. , Twelve Extraordinary Women: How God Shaped Women of the Bible, and What He Wants to Do with You