Actualy quite easy if you quote chapter and verse from the Bible
I researched this so I would be ready to answer questions about Purgatory.
[FONT="]To understand Catholic Doctrine of Purgatory and its basis in Sacred Scripture you first need to understand a few Christian principles.[/FONT]
[FONT="]Principle 1[/FONT][FONT="]; There is a purification after death, i.e., there is punishment for sin even after one has received forgiveness.[/FONT]
[FONT="]Principle 2[/FONT][FONT="]; Nothing unclean, that is nothing tainted with sin, will enter Heaven.[/FONT]
[FONT="]Principle 3[/FONT][FONT="]; There is a process for the spirits of just men to be made perfect.[/FONT]
[FONT="]Principle 4[/FONT][FONT="]; There is a place other than Heaven or Hell, this place involves suffering and loss, and you will remain until no longer “tainted with sin†or “uncleanâ€.[/FONT]
[FONT="]Principle 5[/FONT][FONT="]; There are two judgments.[/FONT]
[FONT="]Principle 6[/FONT][FONT="]; God assists those in this purification in response to the actions of the living.[/FONT]
[FONT="]BASIS IN SCRIPTURE[/FONT]
[FONT="]Principle 1[/FONT][FONT="]; There is punishment for sin even after one has received forgiveness, i.e., purification after death.[/FONT]
2 Samuel 12:13-18 D
avid said to Nathan, "I have sinned against the LORD." And Nathan said to David, "The LORD also has put away your sin; you shall not die. Nevertheless, because by this deed you have utterly scorned the LORD, the child that is born to you shall die." Then Nathan went to his house. And the LORD struck the child that Uri'ah's wife bore to David, and it became sick. David therefore besought God for the child; and David fasted, and went in and lay all night upon the ground. And the elders of his house stood beside him, to raise him from the ground; but he would not, nor did he eat food with them. On the seventh day the child died. And the servants of David feared to tell him that the child was dead; for they said, "Behold, while the child was yet alive, we spoke to him, and he did not listen to us; how then can we say to him the child is dead? He may do himself some harm."
David sinned, confessed and was forgiven, but there was still punishment in that the child still died. David besought God and fasted but still the child died. There is more,
Numbers 20:12
But the LORD said to Moses and Aaron, because you have not believed Me, to treat Me as holy in the sight of the sons of Israel, therefore you shall not bring this assembly into the land which I have given them.
God forgave the incredulity of Moses and Aaron, but in punishment kept them from the “land of promiseâ€.
The analogy that Scott Hahn, a former Protestant minister and now a leading Catholic apologetic, uses is that of someone breaking their neighbor’s window. The neighbor might "forgive" them, but you would still need to replace the window (the damage caused by your deed).
[FONT="]Principle 2[/FONT][FONT="]; Nothing unclean, e.g., nothing that is tainted with sin, will enter Heaven.[/FONT]
[FONT="]Revelation 21:27[/FONT]
[FONT="] But nothing unclean shall enter it, nor any one who practices abomination or falsehood, but only those who are written in the Lamb's book of life.[/FONT]
[FONT="]“Nothing unclean shall enter itâ€, “it†being the New Jerusalem (or Heaven), nothing unclean, nothing tainted with sin will enter Heaven. There is more,[/FONT]
[FONT="]Matthew 5:48 [/FONT]
[FONT="]You, therefore, must be perfect, as your heavenly Father is perfect.[/FONT]
[FONT="]“You, therefore, must be perfectâ€, reinforces Principle 2 that nothing unclean will enter Heaven. But God wants us to be perfect. If we are not perfected by the time we die, we will be perfected in purgatory. He loves us too much to allow us to be less than what he created us to be. Purgatory is not about an angry God inflicting punishment upon his creatures. It is about a loving Father who "disciplines us for our good, that we may share his holiness" (Heb. 12:10). There is more,[/FONT]
[FONT="]Habakkuk 1:12-13[/FONT]
[FONT="] Are You not from everlasting, O LORD, my God, my Holy One? We will not die. You, O LORD, have appointed them to judge; and You, O Rock, have established them to correct. Your eyes are too pure to approve evil, and You can not look on wickedness with favor[/FONT]
[FONT="]God’s “eyes are too pure to behold evil†and “cannot look on wickedness with favorâ€. Whosoever comes into God’s presence must be perfectly pure and any sin is a stain of evil and wickedness reinforcing that we cannot enter Heaven if tainted with sin.[/FONT]
[FONT="]Principle 3[/FONT][FONT="]; There is a process for the spirits of just men to be made perfect. [/FONT]
[FONT="]Hebrews 12:22-23[/FONT]
[FONT="] But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, and to innumerable angels in festal gathering, and to the assembly of the first-born who are enrolled in heaven, and to a judge who is God of all, and to the spirits of just men made perfect,[/FONT]
[FONT="]How are the “spirits of just men made perfect� There has to be a way, a process for the “spirits of just men†to be made “perfect†because of Principle 2 you must be “perfect†to enter Heaven.[/FONT]
[FONT="]Principle 4[/FONT][FONT="]; There is a place other than Heaven or Hell, this place involves suffering and loss, and you will remain until no longer “tainted with sin†or “uncleanâ€.[/FONT]
[FONT="]1 Corinthians 3:13-15 [/FONT]
each man's work will become manifest; for the Day will disclose it, because it will be revealed with fire, and the fire will test what sort of work each one has done. If the work which any man has built on the foundation survives, he will receive a reward. If any man's work is burned up, he will suffer loss, though he himself will be saved, but only as through fire.
[FONT="]Where is this place that you will suffer loss and still be saved? Is it Heaven? You will not suffer loss in Heaven. Is it Hell? You cannot be saved once in Hell. There is more,[/FONT]
[FONT="]Matthew 12:32[/FONT]
[FONT="] And whoever says a word against the Son of man will be forgiven; but whoever speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come.[/FONT]
[FONT="]Where is this place that there is forgiveness in the “age to come� Is it Heaven? You will not need forgiveness in Heaven. Is it Hell? You cannot be saved once in Hell. Or put another way, if there is no purification after death then this passage doesn’t make much sense. Just before this passage in Matthew Jesus had been casting out demons. He announced that the kingdom of God had come so there is no way Matthew 12:32 could be interpreted as saying the age to come was the New Covenant. There is more,[/FONT]
[FONT="]1 Peter 3:18-19[/FONT]
For Christ also died for sins once for all, the righteous for the unrighteous, that he might bring us to God, being put to death in the flesh but made alive in the spirit; in which he went and preached to the spirits in prison,
[FONT="]Where are the “spirits in prison� Heaven in no way could be considered a “prison†and the spirits in Hell cannot be redeemed. There is more,[/FONT]
[FONT="]Matthew 18:32-35[/FONT]
Then his lord summoned him and said to him, `You wicked servant! I forgave you all that debt because you besought me; and should not you have had mercy on your fellow servant, as I had mercy on you?' And in anger his lord delivered him to the jailers, till he should pay all his debt. So also my heavenly Father will do to every one of you, if you do not forgive your brother from your heart."
[FONT="]You will not get out of this place until you have paid all of your debts, until all of your sins have been purified. There is more,[/FONT]
[FONT="]Hebrews 12:9-11[/FONT]
Besides this, we have had earthly fathers to discipline us and we respected them. Shall we not much more be subject to the Father of spirits and live? For they disciplined us for a short time at their pleasure, but he disciplines us for our good, that we may share his holiness. For the moment all discipline seems painful rather than pleasant; later it yields the peaceful fruit of righteousness to those who have been trained by it.
[FONT="]In summary, there is a place that you will suffer loss and still be saved. It is not Heaven or Hell. There is forgiveness in the “age to comeâ€. This forgiveness does not take place in Heaven or Hell. If there is no purification after death then these passages don’t make much sense. Where are the “spirits in prisonâ€? Heaven in no way could be considered a “prison†and the spirits in Hell cannot be redeemed. This “discipline seems painful rather than pleasant†but later yields the “fruit of righteousnessâ€.[/FONT]
[FONT="]Principle 5[/FONT][FONT="]; There are two judgments.[/FONT]
[FONT="]When we die, we undergo what is called the particular, or individual, judgment. Scripture says that "it is appointed for men to die once, and after that comes judgment" (Heb. 9:27). We are judged instantly and receive our reward, for good or ill. We know at once what our final destiny will be. At the end of time, when Jesus returns, there will come the general judgment to which the Bible refers, for example, in Matthew 25:31-32: "When the Son of man comes in his glory, and all the angels with him, then he will sit on his glorious throne. Before him will be gathered all the nations, and he will separate them one from another as a shepherd separates the sheep from the goats." In this general judgment all our sins will be publicly revealed (Luke 12:2–5). It is between the particular and general judgments, then, that the soul is purified of the remaining consequences of sin: "I tell you, you will never get out till you have paid the very last copper" (Luke 12:59). [/FONT]
[FONT="]Principle 6[/FONT][FONT="]; God assists those in this purification in response to the actions of the living.[/FONT]
[FONT="]James 5:15 [/FONT]
[FONT="]The prayer of faith will save the sick man and the Lord will raise him up again; and if he has committed any sins, he will be forgiven.[/FONT]
[FONT="]The following passages make no sense in a Heaven and Hell only theology.[/FONT]
[FONT="]James 5:20[/FONT]
[FONT="] let him know that whoever brings back a sinner from the error of his way will save his soul from death and will cover a multitude of sins.[/FONT]
[FONT="]1 Peter 4:8 [/FONT]
[FONT="]Above all hold unfailing your love for one another, since love covers a multitude of sins.[/FONT]
So far Principles 1-6 are based on Sacred Scripture that the Catholics and Protestants agree upon. The next passage comes from the Septuagint.
2 Maccabees 12:44-45
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
In the Septuagint in 2 Maccabees 12, in which Judah Maccabee and his men pray for their fallen comrades who had "fallen asleep in righteousness" so that they may be "freed from their sins" in the afterlife, and it was a "holy and pious thought" for them to do this. Thus 2 Maccabees endorses praying for the dead that they may be loosed from the consequences of their sins (for it must be the consequences of sin that are in mind since the saved are not sinning in the afterlife). Since it is not pleasant to be bound to the consequences of one's sins, we can infer some kind of pain or discomfort, and thus the full doctrine of purgatory—a purification (freeing) after death, which involves some kind of pain or discomfort, and which can be assisted by the prayers of the living.
Protestant Theology
However, while 2 Maccabees 12 certainly teaches the doctrine of purgatory, the doctrine is in no way "based on" that passage but based upon the principles derived from the numerous passages from our common books listed above, but more fundamentally, it can be derived from the principles of Protestant theology alone.
Protestants are very firm (in fact, insistent) about the fact that we continue sinning until the end of this life because of our corrupt nature. They are equally firm about the fact that we will not be sinning in heaven because we will no longer have a corrupt nature. Thus between death and glory there must be a sanctification—a purification—of our natures whether they admit to it or not. To put it in more Protestant terms, "the final sanctification" or "the last rush of sanctification" is what we Catholics call Purgatory.
Conclusion – Catholic Theology
Purgatory makes sense because there is a requirement that a soul not just be declared to be clean, but must actually be clean, before a man may enter into eternal life. After all, if a guilty soul is merely "covered" if its sinful state still exists but is officially ignored, then it is still a guilty soul. It is still unclean.
Catholic theology takes seriously the notion that "nothing unclean shall enter heaven." From this it is inferred that a less than cleansed soul, even if "covered" remains a dirty soul and isn’t fit for heaven. It needs to be cleansed or "purged" of its remaining imperfections. The cleansing occurs in purgatory. Paul also tells the Corinthians at the Judgment Day “they would be changed and prepared for Heavenâ€. At the Judgment Day this “change†occurs instantly. Indeed, the necessity of the purging is taught in other passages of Scripture, such as 2 Thessalonians 2:13, which declares that God chose us "to be saved through sanctification by the Spirit." Sanctification is thus not an option, something that may or may not happen before one gets into heaven. It is an absolute requirement, as Hebrews 12:14 states that we must strive "for the holiness without which no one will see the Lord."