Introduction:
Catholics believes that acting morally means acting in accordance with the eternal laws of God, which are written into the human hearts so deeply that even those who know nothing of God can follow the path of morality. According to Cynthia Stewart, Nature law, as this interior marking is called, comes to humans through their capacity to reason, which sparks the conscience to respond to the eternal law. This means that people of other religions or the non religious all have the capacity to act as morally as catholic Christians, it is believes that they will struggle more since they will not have the benefit of the sacraments that opens them to grace to resist sin.
Augustine of Hippo (354-430) regarded sin as "...a word, deed or desire contrary to the eternal law." The church classified sin into two parts, they are: mortal and venial sin. Catholic moral theology divides sin into two parts, primarily on the basis of degree and effect:
What is mortal sin?
According to http://www.catholicdoors.com/faq/qu06.htm :
“Mortal sin is a radical possibility of human freedom, as is love itself. It results in the loss of charity and the private of sanctifying grace, that is, of the state of grace. If it is not redeemed by repentance of God's forgiveness, it causes exclusion to make choices for ever, with no turning back. However, although we can judge that an act is in itself a serious offense, we must entrust judgment of persons to the justice and mercy of God.”
For a sin to be mortal, three conditions must be met:
Mortal sin is a sin whose object is a serious matter and which is also committed with full intension awareness and deliberate consent.
A serious matter is specified by the Ten Commandments Corresponding to the answer to the rich young man: ❖ Do not kill ❖ Do not commit adultery ❖ Do not steal ❖ Do not bear false witness ❖ Do not defraud ❖ Honor your