The lower animals cannot sin because the law of their lives is within them, constraining them to act in accordance with its dictates.  Upon man, free to choose, God imposed law.  With freedom of will he received the gift of conscience, which, enabling him to distinguish between right and wrong, invested him with responsibility, and made disobedience sin.  That he can sin is his patent of nobility, that he does sin is his ruin and disgrace.

The effect of sin is separation from God, who can have no fellowship with evil, for sin is the abominable thing which He hates, and on which He cannot even look.  A breach, altogether irreparable on man’s part, was made between man and his Creator when the first transgression of the law of God took place.  The impulse of every sinner, which only Divine power can overcome, is to flee from God.  Hence arises the necessity for reconciliation, and for the intervention of God to effect it.  That the unity thus broken may be restored, expiation must be made by one possessing the nature of the being that had sinned, and yet, by His possession of the Divine nature, investing that expiation with illimitable worth, so that all sin may be covered, and every sinner find a way of escape from the power and the penal consequences of transgression.  These conditions meet in the Lord Jesus Christ and in Him alone.  That God might, without compromising His attributes, be enabled to bring man back into fellowship with Himself, He spared not His own Son, and the Son freely gave Himself to suffering and death for the world’s redemption.

In the felt necessity of atonement, which has associated sacrifice with every religion devised by man, we have evidence of the universality of sin.  All feel its crushing pressure, and fear the punishment which, conscience assures them, is deserved and inevitable.  The heathen confesses it as he prostrates himself before the image of his god, or immolates himself or his fellow-man upon his altar; and the Christian feels and confesses it as, fleeing for refuge, he finds pardon and cleansing in the blood of Jesus Christ.

Sin is original or actual, the former inherited from our parents, the latter, personal transgression of the Divine law.  Every man descending from Adam by ordinary generation is born with the taint of original sin.  As the representative head of humanity, Adam transmitted to all his descendants the nature that his sin had polluted.  The fountain of life was poisoned at its source, and when Adam begat children they were born in his likeness.  “By one man sin entered into the world, and death by sin; and so death passed upon all men.”  “Death reigned ... even over them that had not sinned after the similitude of Adam’s transgression.”  “By one man’s disobedience many were made sinners."[198]