Purgatory

The souls of the dead who are in God’s grace but in need of final purification go through a state called Purgatory.

By his suffering, death and resurrection, Jesus paid the price for our sin and offers man the chance to avoid the eternal consequences of sin, but temporal consequences may still remain.

Every person undergoes a Particular Judgement when they die. If they are in a state of sanctifying grace and free of all sin, they will spend eternity in Heaven with God. People who reject Jesus and are in a state of mortal sin condemn themselves to eternal punishment in Hell.

The souls of people who are in friendship with Jesus and free of mortal sin but have venial sin or other imperfections must undergo a temporary purification before they enter Heaven since nothing unclean or unholy may enter there.

Through the mercy of God, Purgatory removes any attachments or tendencies that would keep a holy person apart from Him.

The souls in Purgatory are on their way to Heaven and not in any danger of going to Hell.

Although suffering, the holy souls in Purgatory are still in communion with the rest of the Church. They cannot pray for themselves but they benefit from the prayers of those in Heaven and on Earth. The holy souls in Purgatory can also pray for us.

Between death and Heaven:

The last step of sanctification:

In need of purification:

The Church gives the name Purgatory to this final purification of the elect, which is entirely different from the punishment of the damned. The Church formulated her doctrine of faith on Purgatory especially at the Councils of Florence and Trent. The tradition of the Church, by reference to certain texts of Scripture, speaks of a cleansing fire: As for certain lesser faults, we must believe that, before the Final Judgment, there is a purifying fire. He who is truth says that whoever utters blasphemy against the Holy Spirit will be pardoned neither in this age nor in the age to come. From this sentence we understand that certain offenses can be forgiven in this age, but certain others in the age to come.
Catechism of the Catholic Church 1031

Sin has consequences:

Eternal and temporary consequences of sin:

If anyone builds on this foundation with gold, silver, precious stones, wood, hay, or straw, the work of each will come to light, for the Day will disclose it. It will be revealed with fire, and the fire [itself] will test the quality of each one’s work. If the work stands that someone built upon the foundation, that person will receive a wage. But if someone’s work is burned up, that one will suffer loss; the person will be saved, but only as through fire.
1 Corinthians 3: 12-15

An extension of God’s mercy:

Burning up imperfections:

Not quite ready for Heaven:

In following the Gospel exhortation to be perfect like the heavenly Father during our earthly life, we are called to grow in love, to be sound and flawless before God the Father ‘at the coming of our Lord Jesus with all his saints’. Moreover, we are invited to ‘cleanse ourselves from every defilement of body and spirit’, because the encounter with God requires absolute purity. Every trace of attachment to evil must be eliminated, every imperfection of the soul corrected. Purification must be complete, and indeed this is precisely what is meant by the Church’s teaching on purgatory. The term does not indicate a place, but a condition of existence. Those who, after death, exist in a state of purification, are already in the love of Christ who removes from them the remnants of imperfection
Pope John Paul II, General Audience, August 4, 1999

Holy souls in the Communion of Saints: