My parish had a parish mission last week, and our pastor wanted to advertise that there was a plenary indulgence that one could gain from attending the mission, so he asked me to write an explanation of indulgences for the parish. From what I wrote, he streamlined it down to a few bullet points (I tend to be a bit verbose, if you hadn't already noticed).
For my draft, I looked at Catholic Answers' Primer on Indulgences, and Jimmy Akin's article How to Gain an Indulgence, and tried to combine them and make the piece a little more reader-friendly for people who don't have much knowledge of the faith.
A lot of misinformation is given about indulgences and the Catholic Church. The Church never “got rid” of indulgences. At the Council of Trent (session 25), the Church infallibly defined indulgences as a valid part of the faith, condemning the beliefs that a) indulgences are useless and b) the Church doesn’t have the power to grant them. Both of those are false, and Catholics are not permitted to spread them. So what are indulgences? Hopefully the following will help answer that question:
The results of sin: guilt and punishment:
When we sin, we incur guilt: “When a man or woman commits sins, that person is guilty.” (cf. Numbers 5:6) We have broken our relationship with God and other people. We also incur punishment relative to the offense we committed: “I will punish you according to the fruit of your doings, says the LORD.” (Jeremiah 21:14) Punishment is meant to correct us so that we recognize the evil we have committed and convert to doing good in the future. “Be afraid of the sword, for wrath brings the punishment of the sword, that you may know there is a judgment." (Job 19:29) It is important to remember that we bring these punishments on ourselves. God wants all of us to be with Him; He wants us to do good. God is not trying to trap us into doing evil. His punishments reprimand us for our bad deeds. If we humbly accept our just punishments, they will help us to act rightly in the future. God can reduce someone’s punishment, and He does so through indulgences.
Punishments are of two types: Temporal and Eternal:
Depending on the severity of our sins, our punishment will be more or less severe. Eternal punishment is Hell--being separated from God forever. Hell is the punishment for people who commit mortal (serious, grave) sins and do not repent from them. “They will go away into eternal punishment, but the righteous into eternal life." (Matthew 25:46) It is connected to the guilt of the sin, and it is forgiven through the Sacrament of Reconciliation. There are also temporal punishments (punishments that will end): “The punishment of your iniquity, O daughter of Zion, is accomplished; He will keep you in exile no longer.” (Lamentations 4:22) Indulgences affect temporal punishments.
Forgiveness removes guilt, but not all punishment:
In the Sacrament of Reconciliation, we confess our sins to God through His priest. When we are forgiven, our guilt is completely removed: “I said, ‘I will confess my transgressions to the LORD’; then thou didst forgive the guilt of my sin.” (Psalm 32:1) The punishment, however, remains. Moses is a good example of this. God forgave Moses’ guilt, but He still punished Moses by not allowing him to live long enough to enter the Promised Land. (Numbers 20:12) Death itself is a punishment that comes from sin. (Genesis 3:22-24; Romans 5:12) Even though we are forgiven of sins through the sacraments, we will still die. If I were to go to Confession for stealing someone’s car, I would be forgiven of the guilt, but I would still have the car that is someone else’s property. We all recognize that I must (at least) restore the stolen property. The same goes for all sins. There are temporal effects of our sins and through our punishment we restore them. Less objective sins like gossip, sloth, lust, etc. are much harder to restore. Therefore, God disciplines us through other punishments. God gave us the sacraments to remove our guilt and He allows us indulgences to reduce our punishments.
God allows us to do good in order to take away the punishment of others:
Just like Jesus died on the cross for all of us, so we can unite our little sacrifices to Him for the benefit of others. Similarly, God was ready to take away the punishment of Sodom if Abraham could find enough righteous men. (Genesis 18:16-33) Also, Jesus forgave the sins of the paralytic man because he saw the faith of the man’s friends. (Matthew 9:2) God allows us to gain indulgences not just for ourselves, but also to help others.
God works through His Church:
Just as we receive the sacraments from God through His Church, so also God offers us indulgences through the Church. The penance given in the Sacrament of Reconciliation has been given since its foundation because the Church recognized that restitution needed to be made. The sinner needed to do something to amend the situation beyond being forgiven of the guilt. The Church alone has the authority to grant indulgences.
“In the early Church, penances were sometimes severe. For serious sins, such as apostasy, murder, and abortion, the penances could stretch over years, but the Church recognized that repentant sinners could shorten their penances by pleasing God through pious or charitable acts that expressed sorrow and a desire to make up for one’s sin . . . If Christ gave his ministers the ability to forgive the eternal penalty of sin, how much more would they be able to remit the temporal penalties of sin! Christ also promised his Church the power to bind and loose on earth, saying, ‘Truly, I say to you, whatever you bind on earth shall be bound in heaven, and whatever you loose on earth shall be loosed in heaven’ (Matt. 18:18). As the context makes clear, binding and loosing cover Church discipline, and Church discipline involves administering and removing temporal penalties (such as barring from and readmitting to the sacraments). Therefore, the power of binding and loosing includes the administration of temporal penalties.”
Indulgences can be applied to the dead:
If we die with punishments unfulfilled, we cannot yet enter Heaven: “Nothing unclean shall enter [Heaven].” (Revelation 21:27) Because of that, we must be cleansed of any leftover temporal punishments before entering Heaven. That is what Purgatory does—it “purges” us of any leftover guilt and punishment. The purification that happens in Purgatory is often likened to fire, purifying precious metal: “If any man's work is burned up, he will suffer loss, though he himself will be saved, but only as through fire.” (1 Corinthians 3:15) We can offer indulgences for the sake of those who are in Purgatory (so that their purgation may be swifter and their entrance into Heaven sooner/easier).
An example of this is Judas Maccabeus who, after a battle, gathered his soldiers’ dead bodies and found that all of the slain soldiers were wearing superstitious amulets (an great offense against God because we must put our trust in Him alone, not in superstitions).
[Judas and his people] turned to prayer, beseeching that the sin which had been committed might be wholly blotted out. And the noble Judas exhorted the people to keep themselves free from sin, for they had seen with their own eyes what had happened because of the sin of those who had fallen. He also took up a collection, man by man, to the amount of two thousand drachmas of silver, and sent it to Jerusalem to provide for a sin offering. In doing this he acted very well and honorably, taking account of the resurrection. For if he were not expecting that those who had fallen would rise again, it would have been superfluous and foolish to pray for the dead. But if he was looking to the splendid reward that is laid up for those who fall asleep in godliness, it was a holy and pious thought. Therefore he made atonement for the dead, that they might be delivered from their sin. (2 Maccabees 12:42-45)
Certainly when it comes to the eternal effects of our sins, only Christ can make amends or reparation. Only he was able to pay the infinite price necessary to cover our sins. We are completely unable to do so, not only because we are finite creatures incapable of making an infinite satisfaction, but because everything we have was given to us by God. For us to try to satisfy God’s eternal justice would be like using money we had borrowed from someone to repay what we had stolen from him. No actual satisfaction would be made (cf. Ps. 49:7-9, Rom. 11:35). This does not mean we can’t make amends or reparation for the temporal effects of our sins. If someone steals an item, he can return it. If someone damages another’s reputation, he can publicly correct the slander. When someone destroys a piece of property, he can compensate the owner for its loss. All these are ways in which one can make at least partial amends for what he has done.
An excellent biblical illustration of this principle is given in Proverbs 16:6, which states: ‘By loving kindness and faithfulness iniquity is atoned for, and by the fear of the Lord a man avoids evil’ (cf. Lev. 6:1-7; Num. 5:5-8). Here we are told that a person makes temporal atonement (though never eternal atonement, which only Christ is capable of doing) for his sins through acts of loving kindness and faithfulness.
How to gain an indulgence:
To gain any indulgence you must be a Catholic in a state of grace. You must be a Catholic in order to be under the Church's jurisdiction, and you must be in a state of grace because apart from God's grace none of your actions are fundamentally pleasing to God (meritorious). You also must have at least the habitual intention of gaining an indulgence by the act performed.
To gain a partial indulgence, you must perform with a contrite heart the act to which the indulgence is attached.
To gain a plenary indulgence [full cleansing from all punishments] you must perform the act with a contrite heart, plus you must go to confession [within a short period of time—around 8 days] (one confession may suffice for several plenary indulgences), receive Holy Communion, and pray for the pope's intentions. (An Our Father and a Hail Mary said for the pope's intentions are sufficient, although you are free to substitute other prayers of your own choosing.) The final condition is that you must be free from all attachment to sin, including venial sin.
Because of the extreme difficulty in meeting the final condition, plenary indulgences are rarely obtained. If you attempt to receive a plenary indulgence, but are unable to meet the last condition, a partial indulgence is received instead.