The foundation of our love and devotion for the poor souls in purgatory is this: “If one member suffer any thing, all the members suffer with it; or if one member glory, all the members rejoice with it” (I Cor. 12:26).
This is the bond of charity that binds the Church Militant to the Church Suffering and the Church Triumphant. Just as we glory in the saints and are uplifted by their victories on Earth and in Heaven, we also suffer with the souls detained in the prison of Purgatory. This is the meaning of the word “compassion”: to suffer with. Bound to them by Christian charity, our souls burn to share in their sufferings and alleviate their burdens.
A well known liturgical tradition bears this out perfectly: Ash Wednesday. In ancient times, a public sinner guilty of grave sin was required to do public penance in ashes for a number of years before being received again to Holy Communion. Gradually the faithful, zealous with charity, sought to place upon themselves also this penance to share the burden of their penitent brethren. As it is written, Bear ye one another’s burdens; and so you shall fulfil the law of Christ (Gal. 6:2). Thus did Ash Wednesday become the corporate imposition of ashes as it is today. It is this charity that must burn within us on behalf of the poor souls.
We must all be in the habit of offering penance for our brother. When any Christian sees the sins of others, he imitates Christ by offering penance for that sin. How many of us have grown angry at the sins of the clergy? How many have burned with zeal over the sins of this dark world, the offenses against God? As the Prophet says, “the zeal of thy house hath eaten me up: and the reproaches of them that reproached thee are fallen upon me” (Ps. 68:10). Through charity, this zeal is turned into penance for their sin. Imitating Christ, the Christian offers the suffering of penance for sinners. As Isaias says, “he hath borne the sins of many, and hath prayed for the transgressors” (Is. 53:12).
This zealous charity causes us to offer penance for the poor souls. They are now receiving the temporal punishment for their sins. Let us also take upon ourselves their punishment, in order to glorify God and free them from their bonds. There are many ways to do this. The Church incorporates this prayer at the end of every hour of the divine office: “May the souls of the faithful, through the mercy of God, rest in peace. Amen.”
In every Mass, the faithful departed are prayed for and the merits of the Mass applied to them. There are prayers for every weekday for the poor souls, as well as the Novena for the poor souls. We should all be in the habit of praying for the poor souls every day. We can also publicly pray for recently departed souls: whenever you hear that anyone has died, make the sign of cross.
The plenary indulgence
The most potent devotion is the plenary indulgence. The word indulgence means “kind pardon.” It refers to an act wherein God, in view of the merits of Christ and the saints, grants remission of temporal punishment due to sin for some soul. In other words, God permits the saints to truly share the burden of penance incumbent upon every soul. Every sin has its due penance (temporal punishment) to repair God’s glory and cleanse the sinner from his sin. This penance is also known as “satisfaction.” St. Thomas speaks concerning the indulgence in this way:
Now one man can satisfy for another[.] … And the saints in whom this super-abundance of satisfactions is found, did not perform their good works for this or that particular person … but they performed them for the whole Church in general, even as the Apostle declares that he fills up “those things that are wanting of the sufferings of Christ … for His body, which is the Church” to whom he wrote (Colossians 1:24). These merits, then, are the common property of the whole Church. Now those things which are the common property of a number are distributed to the various individuals according to the judgment of him who rules them all. Hence, just as one man would obtain the remission of his punishment if another were to satisfy for him, so would he too if another’s satisfactions be applied to him by one who has the power to do so. (ST Suppl. Q25 a1)
Here St. Thomas explains the logic of the indulgence in the sharing of burdens mentioned above. If we sinners can share the burdens of grave sinners with our small penances, how much more can the penances of the saints satisfy for the punishments due to sin and, yet more, the infinite merits of Christ? Thus does the Church distribute these merits gained by Christ and the saints to poor sinners of the Church Suffering. It is His mercy that we also participate in this by gaining an indulgence.
St. Thomas then explains the method of receiving and applying an indulgence.
That [indulgences] should be applied demands, firstly, authority to dispense this treasure; secondly, union between the recipient and Him Who merited it — and this is brought about by charity; thirdly, there is required a reason for so dispensing this treasury, so that the intention, namely, of those who wrought these meritorious works is safeguarded, since they did them for the honor of God and for the good of the Church in general (ST Suppl. Q25 a2).
Here he explains the union in charity and intention between God and the Church in her three parts — Triumphant, Suffering, and Militant. The indulgence is a unique manifestation of the bond of charity in the Communion of Saints. The living faithful soul unites his intentions to that of the Church authority in granting the indulgence, which unites to the saints in heaven perfected in Christ, all for the benefit of some soul in Purgatory.
From here comes the general requirements for obtaining any indulgence for the poor souls: Confession, Holy Communion, prayers for the Roman pontiff and his intentions, as well as detachment from every sin, even venial. The confession must be completed “several days” before or after the indulgence (generally understood as eight days), which can applied to multiple plenary indulgences. However, Holy Communion and prayer for the Roman pontiff must be completed on every day that an indulgence is obtained. Only one plenary indulgence can be obtained per day .
But how can we pray for the intentions of Pope Francis when they are evidently against the Catholic Faith? As Peter Kwasniewski explains, by the nature of his office, the intentions of the Roman pontiff always include the following:
- The progress of the Faith and triumph of the Church
- Peace and union among Christian princes and rulers
- The conversion of sinners
- The uprooting of heresy
Whatever other intentions may be in the mind of Pope Francis, in the supernatural order, they cannot ever contradict these. Thus, we may pray without any anxiety for the intentions of the pope to gain the indulgence.
Three common plenary indulgences available throughout the year
Unfortunately, because charity for the poor souls has grown so cold in recent times, many of the current indulgences authorized are not accessible online to the faithful. They are contained, instead, in the Manual of Indulgences cited below. Fortunately, the celebrated Raccolta does still contain a great number of indulgenced prayers and practices for the faithful. Here we will share three easily obtained plenary indulgences contained in the Manual of Indulgences currently in force.
The first is the holy rosary:
A plenary indulgence is granted to the faithful who devoutly recite the Marian rosary in a church or oratory, or in a family, or religious community or an association of the faithful and in general when several of the faithful gather for the summer on his purpose. 
This indulgence is granted with a few conditions in praying the rosary itself: it must be at least one third (that is, five decades of the total fifteen), and they must be said consecutively. In public recitation, the mysteries must be announced “according to local custom,” but in private the faithful may “simply join in meditation.” Thus this plenary indulgence can be easily obtained by daily communicants who pray a family rosary.
Another common indulgence is Eucharistic Adoration. A plenary indulgence is provided for “the faithful who visit the Blessed Sacrament for adoration lasting at least half an hour” . Make sure to use your Holy Hours to benefit the holy souls.
Finally, another simple plenary indulgence is gained by devout reading of the Holy Scriptures. This indulgence is helpful because it does not require its completion at a set location.
A plenary indulgence is granted to the faithful who read Scripture as spiritual reading from a text approved by competent authority and with the reverence due to the divine word for at least a half an hour.
Here the decree tacitly contrasts “spiritual reading” from mere intellectual study of the Holy Bible as Protestants or secularists are wont to do. Spiritual reading instead is meant in the same way as one would read the spiritual classics such as the Imitation of Christ: slowly, devoutly, humbly, with prayer. Place yourself in the presence of God, and then read the Scriptures before Him.
These simple indulgences can easily be worked into your spiritual discipline each month, hinging on a regular confession. In gaining indulgences, we increase in charity and merit before God. This helps us overcome our own sin as well and keep eternity before our eyes. This month, take the time to form disciplines for the sake of the holy souls. Do not forget them. Rest eternal grant unto them, O Lord, and let light perpetual shine upon them.
 This satisfaction can be “partial” or “plenary.” Here we will discuss only plenary indulgences, which remit all of the penance incumbent upon a soul.
 Enchiridion Indulgentiarum Normae et Concessiones (Libreria Editrice Vaticana: 2006. Third printing USCCB, 2013), 17-18
 Ibid., 58
 Ibid., 48
 Ibid., 100