The Roman Catholic church teaches that those who are perfect at death are admitted to heaven. Those who are not perfectly cleansed and are still tainted with the guilt of venial sins, however, do not go to heaven but rather go to purgatory where they allegedly go through a process of cleansing (or "purging"). Such souls are oppressed with a sense of deprivation and suffer certain pain. How long they stay in purgatory - and how much suffering they undergo while there - depends upon their particular state of sin.
Roman Catholics also teach that a person's time in purgatory may be shortened, and his pains alleviated, by the faithful prayers and good works of those still alive. The sacrifice of the Mass is viewed as especially important in this regard. Catholics find support for this doctrine in the apocryphal book 2 Maccabees 12:42-45.
That purgatory is a false doctrine is easy to prove from the Scriptures. When Jesus died on the cross, He said "It is finished" (John 19:30). Jesus completed the work of redemption at the cross. In His high priestly prayer to the Father, Jesus said, "I have brought you glory on earth by completing the work you gave me to do" (John 17:4). Hebrews 10:14 emphatically declares, "By one sacrifice he has made perfect for ever those who are being made holy." Hence, those who believe in Christ are "made perfect" forever; no further "purging" is necessary. First John 1:7 says, "The blood of Jesus, his Son, purifies us from all sin." Romans 8:1 says, "Therefore, there is now no condemnation for those who are in Christ Jesus."
Jesus took care of "purging" our sins by His work of salvation at the cross. Hebrews 1:3 affirms, "After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven." Jesus provided full purification for our sins.