A Lutheran friend of mine recently brought up the idea of purgatory on his Facebook. Forgive me but I cannot recall his exact question but it was a pretty basic and just asking people what they thought about it.
First of all, I think the first thing when broaching the topic of purgatory is pointing out what purgatory is NOT. Purgatory is not a second chance. It is not a third place to go when we die because we were not good enough for heaven but not bad enough for hell.
The Catholic Church teaches that when a person dies they are bound for either heaven or hell. The Church teaches that those people who are assured of their salvation but still yet "imperfectly purified" undergo a purification so that they will achieve that holiness that is necessary for entrance into Heaven. This place where we receive this purification is called "purgatory."
Why is it necessary to receive purification if Jesus died for our sins?? Well, Jesus' death and resurrection was the perfect sacrifice that allows us to go to Heaven. Nothing we can do could ever "merit" our going to Heaven---only Jesus' death. In the book of Revelation we are told that "nothing unclean shall enter Heaven." (Rev 21:27) If nothing unclean shall enter Heaven then how are we made clean? We are made clean, or purified, in purgatory.
Let's try to find a simpler way to put it. Our salvation has been bought and paid for by Christ's suffering and death on Calvary. We can lose our salvation though by sinning. When we sin, we are turning away for God and choosing our own way as opposed to His way. We are choosing life without Him. We are all sinners though and thankfully for us, God grants us His mercy and forgiveness and all we have to do is turn back to Him. We are still stained by that sin we committed though even if we are forgiven. There has to be some way to have that stain removed from us prior to entering Heaven. Purgatory is that way that we are purified to free us from the "temporal punishment of sin."
Think of our own children. Imagine they sneak outside and play in the mud even though they were told to stay in the house. They come to us knowing they messed up and are sorrowful. We forgive them but they have to get cleaned up because we are going to church. Wait--going to church won't work. No kid in his right mind wants to go to church. McDonald's!!!! They have to get cleaned up before they go to McDonald's----one with those big playgrounds. The child has been forgiven for getting all muddy but they have to be cleaned up prior to going to play McDonald's. That is like us. God forgives us for our sins but we have to be cleansed prior to going into Heaven. At least according to scripture---if you believe scripture. Purgatory is that cleansing. Is it painful?? I can't say but by reading the passages in the Bible that speak of purification I'm going to guess it isn't exactly pleasant. I would rather be made clean by the blood of the Lamb and be in God's presence than to be considered a pile of dung covered by snow though.
The belief in purgatory is simple and really not something that we should argue over. The Church teaches that prior to getting into Heaven we have to be purified. It doesn't deny Christ's sacrifice or what it did for us. Secondly, we need to be careful that we don't just aim for purgatory----we might miss.
One last thing---I realize that my comparison to us and sin to a child playing in the dirt is not perfect. God gives us free will allows us to wallow in that mud pit if we so choose. At some point we have to get out of it and turn back to Him so that we can go to play McDonalds.