Justification through faith alone: The Roman Catholic Church does not like the Protestant view of justification. It has pronounced anathema upon anyone who believes or teaches this doctrine. Roman Catholic theologians argue that Luther’s doctrine of justification is a legal fiction. They ask: How is it possible for God to pronounce righteous a person who is clearly unrighteous? So in their view God must make a person right before He can pronounce them to be right. It is for this reason that Rome believes justification to be a process that may be lost. Protestants have no difficulty in answering this question. They argue that the reason God can pronounce an unrighteous person to be righteous is because He gives righteousness to every genuine believer in Christ. When God looks at a believer He chooses not to see the sin in that believer, but rather looks at the righteousness of His own Son, imputed to the believer.
Rome’s big mistake is to confuse justification and sanctification. Justification is a one time event that takes place the moment a person believes in Jesus Christ. It cannot be improved on and it cannot be lost. Sanctification is most certainly a process that takes place in every justified person. You cannot separate justification and sanctification – they are two sides of the same coin. When God grants faith to a person so that they come to faith in Jesus Christ, He also gives them the gift of sanctification. Every true believer has the Holy Spirit living in them. The Holy Spirit enables the true believer to grow in holiness and Christ-likeness.