Catholic Purgatory Scriptures

Belief in purgatory is part of Catholic doctrine. Purgatory in the Catholic religion is defined as the period of purification before heaven. This final purification is not the same as punishment for the damned, but rather an opportunity to cleanse oneself of sin as it is impossible for an unclean person to enter heaven.
Purpose of purgatory
The Catholic religion cites a number of scriptural references to the existence of purgatory. An ancient Jewish scripture, "Therefore [Judas Maccabeus] made atonement for the dead, that they might be delivered from their sin." (2 Macc 12:46), lays the foundation of purgatory. In Matthew 5:48, Jesus says, "be perfect, even as your heavenly Father is perfect." This scripture reinforces the belief that purification is necessary after death since perfection is not attainable during life.
Evidence of purgatory
In 1 Peter 3:19; 4:6 Jesus preached to the spirits in the "prison," indicating a place that is not heaven or hell where spirits can receive instruction and make changes to the soul. Philippians 2:10 reads "that at the name of Jesus every knee should bow, in heaven and on earth and under the earth." This scripture indicates three places of celestial importance: in heaven, on earth and under the earth. Though some scholars believe that "under the earth" refers to hell, it is unlikely that occupants of hell would submit to Jesus and bow to him.
Catholics reference the Old Testament, New Testament, Catechism and ancient Jewish scripture when teaching about purgatory. Purgatory is not perceived as a place of punishment or reward, but as a place of the contemplation and growth necessary to enter heaven.