Does a single plenary indulgence remit us from the temporal punishments of all the sins I have ever done in my life?

What is an indulgence?

Sin leads to the possibility of two consequences: 

1. Eternal consequence: If there is no repentance, the soul will be confined to hell for eternity. This consequence can be remitted by receiving forgiveness of sin through the  Sacrament of Reconciliation.
2. Temporal consequence: It is a temporary punishment which remains even after receiving forgiveness of sin (where only the guilt incurred by the act is forgiven)

The doctrine of temporal consequence is based on the Scriptural understanding of what is written regarding forgiveness of sin. Adam and Eve were cast out of the garden as a consequence of eating the forbidden fruit (Genesis 3:24) and the Israelites were made to wander the desert before reaching the promised land because they tested God due to their unbelief (Numbers 14:20-23) even though their sins were forgiven. Temporal punishment can also be seen in the life of David where, even though God put away his sin, he suffers the loss of his child (2 Samuel 12:13-14). This suffering that we endure can be seen as God’s way of loving discipline (Hebrews 12:5-6) which is used to make us realise how grave sin is. This could take place either during our time on Earth or in Purgatory. Temporal punishment can be compared to what a parent does when a child commits a mistake like not doing his homework. He may forgive the child for not doing his work but may also give a temporary punishment such as not permitting the child to watch his favourite cartoon for a day or two so that the child may realise the seriousness of the matter and not repeat it again. 

As we have now understood what temporal punishment is let us see how one can reduce or eliminate this by making amends for our sins. The Catholic Church has traditionally identified three major ways – prayer, fasting, and almsgiving. This healing that we receive can be utilised not just for our sake but also that of others. This is based on the belief that we all form the same body of Christ (Romans 12:5) and just as each organ shares in the life of the whole body, so does each of the faithful profit by the prayers and good works of all the rest.  

Another method of expiation is through indulgences where the Church with the authority given to her (Matthew 16:19) makes use of the merits of Christ (which is enough to amend for all sins) and the merits of the saints (which was more than what was required by them), combinedly called the Church’s treasury (CCC 1476), for the remission of temporal punishment. In order to gain this indulgence one may have to perform certain meritorious tasks as prescribed by the Church. This may include going for confession, receiving Communion, praying for the intentions of the Holy See, works of charity etc. Thus indulgences encourages believers to take part in the sacraments and helps them in attaining a conscience free of sin and its effects. This also leads them to do works that are not just good for themselves but also for their fellow human beings and ultimately brings forth the glory of God.

What are the two types of indulgences?

An indulgence is partial or plenary according as it removes either part or all of the temporal punishment due to sin. – CCC 1471

Who can benefit from indulgences?

The faithful can gain indulgences for themselves or apply them to the dead. – CCC 1471

It is clear from these that plenary indulgence removes all of the temporal punishment due to sins whose guilt has already been forgiven. It would therefore include all the sins that we have acknowledged to a priest during a sincere confession (even those that we have forgotten to confess). 

Now that we know about this, let’s be prudent and utilise the next opportunity that the Church gives us and make use of this wonderful gift.